diff --git a/src/entities/hatch.rs b/src/entities/hatch.rs
index deb8d1351..0dbcb665a 100644
--- a/src/entities/hatch.rs
+++ b/src/entities/hatch.rs
@@ -87,7 +87,7 @@ fn apply_transform(h: &mut Hatch, t: &EntityTransform) {
         if len2 < 1e-12 {
             return;
         }
-        let line_angle_deg = dy.atan2(dx).to_degrees();
+        let line_angle = dy.atan2(dx);
         for path in &mut entity.paths {
             for edge in &mut path.edges {
                 match edge {
@@ -113,8 +113,8 @@ fn apply_transform(h: &mut Hatch, t: &EntityTransform) {
                             p2,
                         );
                         let tmp = a.start_angle;
-                        a.start_angle = 2.0 * line_angle_deg - a.end_angle;
-                        a.end_angle = 2.0 * line_angle_deg - tmp;
+                        a.start_angle = 2.0 * line_angle - a.end_angle;
+                        a.end_angle = 2.0 * line_angle - tmp;
                     }
                     BoundaryEdge::EllipticArc(e) => {
                         crate::scene::transform::reflect_xy_point(
@@ -131,8 +131,8 @@ fn apply_transform(h: &mut Hatch, t: &EntityTransform) {
                         e.major_axis_endpoint.x = 2.0 * dot * ax / len2 - rx;
                         e.major_axis_endpoint.y = 2.0 * dot * ay / len2 - ry;
                         let tmp = e.start_angle;
-                        e.start_angle = 2.0 * line_angle_deg - e.end_angle;
-                        e.end_angle = 2.0 * line_angle_deg - tmp;
+                        e.start_angle = 2.0 * line_angle - e.end_angle;
+                        e.end_angle = 2.0 * line_angle - tmp;
                     }
                     BoundaryEdge::Spline(s) => {
                         for cp in &mut s.control_points {
diff --git a/src/modules/home/inquiry/divide.rs b/src/modules/home/inquiry/divide.rs
index 6a7356d7a..cdaaab6b9 100644
--- a/src/modules/home/inquiry/divide.rs
+++ b/src/modules/home/inquiry/divide.rs
@@ -183,7 +183,7 @@ fn point_at_distance(entity: &EntityType, d: f64) -> Option<Vector3> {
             let span = arc_span_rad(a.start_angle, a.end_angle);
             let t = d / a.radius; // arc_length = r * theta
             if t > span { return None; }
-            let angle = a.start_angle.to_radians() + t;
+            let angle = a.start_angle + t;
             Some(Vector3::new(
                 a.center.x + a.radius * angle.cos(),
                 a.center.y + a.radius * angle.sin(),
@@ -227,7 +227,7 @@ fn point_at_distance(entity: &EntityType, d: f64) -> Option<Vector3> {
     }
 }
 
-fn arc_span_rad(start_deg: f64, end_deg: f64) -> f64 {
-    let span = ((end_deg - start_deg) + 360.0) % 360.0;
-    if span < 1e-6 { 2.0 * PI } else { span.to_radians() }
+fn arc_span_rad(start: f64, end: f64) -> f64 {
+    let span = (end - start).rem_euclid(2.0 * PI);
+    if span < 1e-6 { 2.0 * PI } else { span }
 }
diff --git a/src/modules/home/modify/array.rs b/src/modules/home/modify/array.rs
index 9ff14ca08..8678a3cb0 100644
--- a/src/modules/home/modify/array.rs
+++ b/src/modules/home/modify/array.rs
@@ -531,8 +531,8 @@ impl ArrayPathCommand {
             }
             EntityType::Arc(a) => {
                 let (cx, cy, r) = (a.center.x as f32, a.center.y as f32, a.radius as f32);
-                let a0 = a.start_angle.to_radians() as f32;
-                let a1 = a.end_angle.to_radians() as f32;
+                let a0 = a.start_angle as f32;
+                let a1 = a.end_angle as f32;
                 let span = {
                     let s = fn_norm(a1) - fn_norm(a0);
                     if s <= 0.0 {
diff --git a/src/modules/home/modify/break_cmd.rs b/src/modules/home/modify/break_cmd.rs
index 3c615ac49..c6e07f769 100644
--- a/src/modules/home/modify/break_cmd.rs
+++ b/src/modules/home/modify/break_cmd.rs
@@ -235,21 +235,20 @@ fn break_ellipse(ell: &EllipseEnt, p1: Vec3, p2: Vec3) -> Vec<EntityType> {
 
 // ── Small utilities ────────────────────────────────────────────────────────
 
-/// Returns the angle (degrees, 0-360) of `pt` viewed from (cx, cy) in the XZ plane.
+/// Returns the angle (radians, 0-2π) of `pt` viewed from (cx, cy) in the XZ plane.
 fn angle_on_arc(cx: f32, cy: f32, pt: Vec3) -> f32 {
     let dx = pt.x - cx;
     let dy = pt.z - cy; // XZ plane
-    let a = dy.atan2(dx).to_degrees();
-    (a + 360.0) % 360.0
+    dy.atan2(dx).rem_euclid(std::f32::consts::TAU)
 }
 
 /// Clamp angle `a` to within the arc's angular range (CCW from `start` to `end`).
 fn clamp_to_arc(a: f32, start: f32, end: f32) -> f32 {
-    let span = ((end - start) + 360.0) % 360.0;
-    let rel = ((a - start) + 360.0) % 360.0;
+    let span = (end - start).rem_euclid(std::f32::consts::TAU);
+    let rel = (a - start).rem_euclid(std::f32::consts::TAU);
     if rel <= span {
         a
-    } else if rel < span + (360.0 - span) / 2.0 {
+    } else if rel < span + (std::f32::consts::TAU - span) / 2.0 {
         end
     } else {
         start
diff --git a/src/modules/home/modify/explode.rs b/src/modules/home/modify/explode.rs
index d2697c677..e76a7cf28 100644
--- a/src/modules/home/modify/explode.rs
+++ b/src/modules/home/modify/explode.rs
@@ -273,10 +273,10 @@ fn bulge_to_arc(
 
     // acadrust arcs are always CCW: positive bulge → CCW from p0 to p1
     // Negative bulge → CW from p0 to p1 = CCW from p1 to p0
-    let (start_deg, end_deg) = if b > 0.0 {
-        (norm_deg(a0_rad.to_degrees()), norm_deg(a1_rad.to_degrees()))
+    let (start_angle, end_angle) = if b > 0.0 {
+        (norm_angle(a0_rad), norm_angle(a1_rad))
     } else {
-        (norm_deg(a1_rad.to_degrees()), norm_deg(a0_rad.to_degrees()))
+        (norm_angle(a1_rad), norm_angle(a0_rad))
     };
 
     let mut common = common_src.clone();
@@ -286,16 +286,15 @@ fn bulge_to_arc(
         common,
         center: Vector3::new(cx, cy, elevation),
         radius: r,
-        start_angle: start_deg,
-        end_angle: end_deg,
+        start_angle,
+        end_angle,
         ..ArcEnt::new()
     };
     Some(EntityType::Arc(arc))
 }
 
-fn norm_deg(a: f64) -> f64 {
-    let t = TAU.to_degrees();
-    ((a % t) + t) % t
+fn norm_angle(a: f64) -> f64 {
+    ((a % TAU) + TAU) % TAU
 }
 
 fn explode_mline(ml: &MLine) -> Vec<EntityType> {
diff --git a/src/modules/home/modify/fillet.rs b/src/modules/home/modify/fillet.rs
index 62cd03281..75acd2ffa 100644
--- a/src/modules/home/modify/fillet.rs
+++ b/src/modules/home/modify/fillet.rs
@@ -149,16 +149,15 @@ fn compute_fillet(
     let arc_cx = px + arc_dist * bx / blen;
     let arc_cy = py + arc_dist * by / blen;
 
-    // Arc angles in degrees
-    let a_start_deg = (t1[1] - arc_cy).atan2(t1[0] - arc_cx).to_degrees();
-    let a_end_deg = (t2[1] - arc_cy).atan2(t2[0] - arc_cx).to_degrees();
+    let a_start = (t1[1] - arc_cy).atan2(t1[0] - arc_cx);
+    let a_end = (t2[1] - arc_cy).atan2(t2[0] - arc_cx);
 
     // Pick CCW direction that fills the concave corner
     let cross = dir1[0] * dir2[1] - dir1[1] * dir2[0];
-    let (start_deg, end_deg) = if cross <= 0.0 {
-        (a_start_deg, a_end_deg)
+    let (start_angle, end_angle) = if cross <= 0.0 {
+        (a_start, a_end)
     } else {
-        (a_end_deg, a_start_deg)
+        (a_end, a_start)
     };
 
     // Trim l1 to T1 and l2 to T2
@@ -171,8 +170,8 @@ fn compute_fillet(
     arc.common.handle = Handle::NULL;
     arc.center = Vector3::new(arc_cx, arc_cy, z);
     arc.radius = radius;
-    arc.start_angle = start_deg;
-    arc.end_angle = end_deg;
+    arc.start_angle = norm_angle(start_angle);
+    arc.end_angle = norm_angle(end_angle);
 
     Some((
         EntityType::Line(new_l1),
@@ -265,13 +264,9 @@ fn line_pts(l: &LineEnt) -> Vec<[f32; 3]> {
     ]
 }
 
-fn arc_pts(cx: f64, cy: f64, r: f64, a0_deg: f64, a1_deg: f64, z: f64) -> Vec<[f32; 3]> {
-    use std::f64::consts::TAU;
-    let fn_norm = |a: f64| -> f64 { ((a % TAU) + TAU) % TAU };
-    let a0 = a0_deg.to_radians();
-    let a1 = a1_deg.to_radians();
+fn arc_pts(cx: f64, cy: f64, r: f64, a0: f64, a1: f64, z: f64) -> Vec<[f32; 3]> {
     let span = {
-        let s = fn_norm(a1) - fn_norm(a0);
+        let s = norm_angle(a1) - norm_angle(a0);
         if s <= 0.0 {
             s + TAU
         } else {
@@ -281,7 +276,7 @@ fn arc_pts(cx: f64, cy: f64, r: f64, a0_deg: f64, a1_deg: f64, z: f64) -> Vec<[f
     let steps = (span.abs() * 20.0).ceil().max(4.0) as usize;
     (0..=steps)
         .map(|i| {
-            let ang = fn_norm(a0) + span * (i as f64 / steps as f64);
+            let ang = norm_angle(a0) + span * (i as f64 / steps as f64);
             [
                 (cx + r * ang.cos()) as f32,
                 (cy + r * ang.sin()) as f32,
@@ -309,41 +304,41 @@ fn entity_pts(e: &EntityType) -> Vec<[f32; 3]> {
 
 // ── Arc geometry helpers ───────────────────────────────────────────────────
 
-/// Extract center, radius, start/end angle (degrees), elevation from an arc.
+/// Extract center, radius, start/end angle (radians), elevation from an arc.
 fn arc_geom(a: &ArcEnt) -> ([f64; 2], f64, f64, f64, f64) {
     ([a.center.x, a.center.y], a.radius, a.start_angle, a.end_angle, a.center.z)
 }
 
-/// Normalize angle to [0, 360).
-fn norm360(a: f64) -> f64 { ((a % 360.0) + 360.0) % 360.0 }
+/// Normalize angle to [0, 2π).
+fn norm_angle(a: f64) -> f64 { ((a % TAU) + TAU) % TAU }
 
 /// Return the CCW angular span from `start` to `end`.
 fn arc_span(start: f64, end: f64) -> f64 {
-    let s = (end - start + 360.0) % 360.0;
-    if s < 1e-6 { 360.0 } else { s }
+    let s = (end - start).rem_euclid(TAU);
+    if s < 1e-6 { TAU } else { s }
 }
 
-/// Project a pick point onto an arc: return the parameter t ∈ [0, 360) = the angle.
+/// Project a pick point onto an arc: return the angle in radians.
 fn arc_angle_at(center: [f64; 2], pt: [f64; 2]) -> f64 {
-    norm360((pt[1] - center[1]).atan2(pt[0] - center[0]).to_degrees())
+    norm_angle((pt[1] - center[1]).atan2(pt[0] - center[0]))
 }
 
 /// Clamp angle `a` into the arc range (CCW from `start` to `end`).
 /// Returns the nearer endpoint if `a` is outside.
 fn clamp_angle_to_arc(a: f64, start: f64, end: f64) -> f64 {
     let span = arc_span(start, end);
-    let rel = (a - start + 360.0) % 360.0;
+    let rel = (a - start).rem_euclid(TAU);
     if rel <= span { a }
-    else if rel < span + (360.0 - span) / 2.0 { end }
+    else if rel < span + (TAU - span) / 2.0 { end }
     else { start }
 }
 
-/// Trim an arc so it goes from `new_start` to `new_end` (both in degrees).
+/// Trim an arc so it goes from `new_start` to `new_end` (both in radians).
 fn trim_arc(orig: &ArcEnt, new_start: f64, new_end: f64) -> ArcEnt {
     let mut a = orig.clone();
     a.common.handle = Handle::NULL;
-    a.start_angle = norm360(new_start);
-    a.end_angle   = norm360(new_end);
+    a.start_angle = norm_angle(new_start);
+    a.end_angle   = norm_angle(new_end);
     a
 }
 
@@ -795,7 +790,7 @@ fn fillet_line_arc(
                 // The tangent point on the arc must be within the arc's angular range
                 let tp_arc_angle = arc_angle_at(ac, tp_arc);
                 let tp_arc_clamped = clamp_angle_to_arc(tp_arc_angle, a_start, a_end);
-                if (norm360(tp_arc_angle) - norm360(tp_arc_clamped)).abs() > 0.5 { continue; }
+                if (norm_angle(tp_arc_angle) - norm_angle(tp_arc_clamped)).abs() > 0.01 { continue; }
 
                 // The tangent point on the line must be on the correct side of the click
                 // (prefer the intersection closest to the click)
@@ -809,8 +804,8 @@ fn fillet_line_arc(
 
                 // Build trimmed arc
                 let arc_click_angle = arc_angle_at(ac, click_arc);
-                let arc_click_rel = (arc_click_angle - a_start + 360.0) % 360.0;
-                let tp_arc_rel = (tp_arc_clamped - a_start + 360.0) % 360.0;
+                let arc_click_rel = (arc_click_angle - a_start).rem_euclid(TAU);
+                let tp_arc_rel = (tp_arc_clamped - a_start).rem_euclid(TAU);
                 let new_arc = if tp_arc_rel <= arc_click_rel {
                     trim_arc(arc, tp_arc_clamped, a_end)
                 } else {
@@ -827,8 +822,8 @@ fn fillet_line_arc(
                 fillet_arc.common.handle = Handle::NULL;
                 fillet_arc.center = Vector3::new(fc[0], fc[1], z);
                 fillet_arc.radius = radius;
-                fillet_arc.start_angle = norm360(fstart);
-                fillet_arc.end_angle   = norm360(fend);
+                fillet_arc.start_angle = norm_angle(fstart);
+                fillet_arc.end_angle   = norm_angle(fend);
 
                 best_dist = dist_total;
                 best = Some((EntityType::Line(new_line), EntityType::Arc(new_arc), EntityType::Arc(fillet_arc)));
@@ -870,12 +865,12 @@ fn fillet_arc_arc(
         let ca1 = clamp_angle_to_arc(arc_angle_at(c1, click1), s1, e1);
         let ca2 = clamp_angle_to_arc(arc_angle_at(c2, click2), s2, e2);
 
-        let new_a1 = if (ic1 - s1 + 360.0) % 360.0 <= (ca1 - s1 + 360.0) % 360.0 {
+        let new_a1 = if (ic1 - s1).rem_euclid(TAU) <= (ca1 - s1).rem_euclid(TAU) {
             trim_arc(a1, ic1, e1)
         } else {
             trim_arc(a1, s1, ic1)
         };
-        let new_a2 = if (ic2 - s2 + 360.0) % 360.0 <= (ca2 - s2 + 360.0) % 360.0 {
+        let new_a2 = if (ic2 - s2).rem_euclid(TAU) <= (ca2 - s2).rem_euclid(TAU) {
             trim_arc(a2, ic2, e2)
         } else {
             trim_arc(a2, s2, ic2)
@@ -909,8 +904,8 @@ fn fillet_arc_arc(
                 let tp2a = arc_angle_at(c2, tp2);
                 let tc1 = clamp_angle_to_arc(tp1a, s1, e1);
                 let tc2 = clamp_angle_to_arc(tp2a, s2, e2);
-                if (norm360(tp1a) - norm360(tc1)).abs() > 0.5 { continue; }
-                if (norm360(tp2a) - norm360(tc2)).abs() > 0.5 { continue; }
+                if (norm_angle(tp1a) - norm_angle(tc1)).abs() > 0.01 { continue; }
+                if (norm_angle(tp2a) - norm_angle(tc2)).abs() > 0.01 { continue; }
 
                 let dist_total = (tp1[0]-click1[0]).hypot(tp1[1]-click1[1])
                                + (tp2[0]-click2[0]).hypot(tp2[1]-click2[1]);
@@ -919,12 +914,12 @@ fn fillet_arc_arc(
                 let ca1 = clamp_angle_to_arc(arc_angle_at(c1, click1), s1, e1);
                 let ca2 = clamp_angle_to_arc(arc_angle_at(c2, click2), s2, e2);
 
-                let new_a1 = if (tc1 - s1 + 360.0) % 360.0 <= (ca1 - s1 + 360.0) % 360.0 {
+                let new_a1 = if (tc1 - s1).rem_euclid(TAU) <= (ca1 - s1).rem_euclid(TAU) {
                     trim_arc(a1, tc1, e1)
                 } else {
                     trim_arc(a1, s1, tc1)
                 };
-                let new_a2 = if (tc2 - s2 + 360.0) % 360.0 <= (ca2 - s2 + 360.0) % 360.0 {
+                let new_a2 = if (tc2 - s2).rem_euclid(TAU) <= (ca2 - s2).rem_euclid(TAU) {
                     trim_arc(a2, tc2, e2)
                 } else {
                     trim_arc(a2, s2, tc2)
@@ -939,8 +934,8 @@ fn fillet_arc_arc(
                 fillet_arc.common.handle = Handle::NULL;
                 fillet_arc.center = Vector3::new(fc[0], fc[1], z);
                 fillet_arc.radius = radius;
-                fillet_arc.start_angle = norm360(fstart);
-                fillet_arc.end_angle   = norm360(fend);
+                fillet_arc.start_angle = norm_angle(fstart);
+                fillet_arc.end_angle   = norm_angle(fend);
 
                 best_dist = dist_total;
                 best = Some((EntityType::Arc(new_a1), EntityType::Arc(new_a2), EntityType::Arc(fillet_arc)));
diff --git a/src/modules/home/modify/join.rs b/src/modules/home/modify/join.rs
index 4d5ef5f31..183c1fd3e 100644
--- a/src/modules/home/modify/join.rs
+++ b/src/modules/home/modify/join.rs
@@ -152,7 +152,7 @@ fn try_join_arcs(arcs: &[&(Handle, &EntityType)]) -> Option<(Vec<Handle>, Vec<En
         if (a.radius - r).abs() > 1e-3 { return None; }
     }
 
-    // Collect (start_deg, end_deg) — normalize CCW into [0, 360)
+    // Collect (start_angle, end_angle) in radians.
     let mut intervals: Vec<[f32; 2]> = segs.iter().map(|(_, a)| {
         [a.start_angle as f32, a.end_angle as f32]
     }).collect();
@@ -164,17 +164,17 @@ fn try_join_arcs(arcs: &[&(Handle, &EntityType)]) -> Option<(Vec<Handle>, Vec<En
     let merged_start = intervals[0][0];
     let mut merged_end   = intervals[0][1];
     for &[s, e] in &intervals[1..] {
-        let span = ((e - merged_end) + 360.0) % 360.0;
-        let gap  = ((s - merged_end) + 360.0) % 360.0;
+        let span = (e - merged_end).rem_euclid(std::f32::consts::TAU);
+        let gap  = (s - merged_end).rem_euclid(std::f32::consts::TAU);
         let _ = span;
         if gap > 1e-3 { return None; } // discontinuous
         merged_end = e;
     }
 
-    let span = ((merged_end - merged_start) + 360.0) % 360.0;
+    let span = merged_end - merged_start;
     let handles: Vec<Handle> = arcs.iter().map(|(h, _)| *h).collect();
 
-    if (span - 360.0).abs() < 0.5 {
+    if (span - std::f32::consts::TAU).abs() < 0.01 {
         // Full circle
         let mut circle = acadrust::entities::Circle::new();
         circle.common = first.common.clone();
diff --git a/src/modules/home/modify/lengthen.rs b/src/modules/home/modify/lengthen.rs
index cbcd26994..f2be7dd66 100644
--- a/src/modules/home/modify/lengthen.rs
+++ b/src/modules/home/modify/lengthen.rs
@@ -144,16 +144,16 @@ fn lengthen_arc(arc: &ArcEnt, pick_pt: Vec3, mode: &LenMode) -> Option<EntityTyp
     let cy = arc.center.z as f32; // Y-up: DXF Y → world Z
 
     // Current arc span
-    let span = arc_span_deg(arc.start_angle, arc.end_angle);
-    let current_arc_len = arc.radius * span.to_radians();
+    let span = arc_span_rad(arc.start_angle, arc.end_angle);
+    let current_arc_len = arc.radius * span;
 
     let new_arc_len = apply_mode(current_arc_len, mode)?;
     if new_arc_len < 1e-10 { return None; }
-    let new_span_deg = (new_arc_len / arc.radius).to_degrees();
+    let new_span = new_arc_len / arc.radius;
 
     // Which end (start or end angle) is closer to pick?
-    let start_rad = arc.start_angle.to_radians();
-    let end_rad   = arc.end_angle.to_radians();
+    let start_rad = arc.start_angle;
+    let end_rad   = arc.end_angle;
 
     let start_pt = Vec3::new(
         cx + arc.radius as f32 * start_rad.cos() as f32,
@@ -168,17 +168,17 @@ fn lengthen_arc(arc: &ArcEnt, pick_pt: Vec3, mode: &LenMode) -> Option<EntityTyp
     let dist_start = (pick_pt - start_pt).length();
     let dist_end   = (pick_pt - end_pt).length();
 
-    let delta_span = new_span_deg - span;
+    let delta_span = new_span - span;
 
     let mut result = arc.clone();
     result.common.handle = Handle::NULL;
 
     if dist_end <= dist_start {
         // Extend end angle
-        result.end_angle = arc.start_angle + new_span_deg;
+        result.end_angle = arc.start_angle + new_span;
     } else {
         // Extend start angle (move start backwards)
-        result.start_angle = arc.end_angle - new_span_deg;
+        result.start_angle = arc.end_angle - new_span;
     }
     let _ = delta_span;
     Some(EntityType::Arc(result))
@@ -257,9 +257,9 @@ fn apply_mode(current: f64, mode: &LenMode) -> Option<f64> {
     }
 }
 
-fn arc_span_deg(start: f64, end: f64) -> f64 {
-    let span = ((end - start) + 360.0) % 360.0;
-    if span < 1e-6 { 360.0 } else { span }
+fn arc_span_rad(start: f64, end: f64) -> f64 {
+    let span = (end - start).rem_euclid(std::f64::consts::TAU);
+    if span < 1e-6 { std::f64::consts::TAU } else { span }
 }
 
 fn xz_to_v3(v: Vec3, z: f64) -> Vector3 {
diff --git a/src/modules/home/modify/offset.rs b/src/modules/home/modify/offset.rs
index 1e555f104..5235bb2e0 100644
--- a/src/modules/home/modify/offset.rs
+++ b/src/modules/home/modify/offset.rs
@@ -394,8 +394,8 @@ fn entity_wire_pts(e: &EntityType) -> Vec<[f32; 3]> {
                 .collect()
         }
         EntityType::Arc(a) => {
-            let a0 = norm_rad(a.start_angle.to_radians());
-            let a1 = norm_rad(a.end_angle.to_radians());
+            let a0 = norm_rad(a.start_angle);
+            let a1 = norm_rad(a.end_angle);
             let span = {
                 let s = a1 - a0;
                 if s <= 0.0 {
diff --git a/src/modules/home/modify/trim.rs b/src/modules/home/modify/trim.rs
index dec7de3f9..8c1b24299 100644
--- a/src/modules/home/modify/trim.rs
+++ b/src/modules/home/modify/trim.rs
@@ -260,8 +260,8 @@ fn build_geos(entities: &[EntityType]) -> Vec<Geo> {
                     cx: a.center.x,
                     cy: a.center.y,
                     r: a.radius,
-                    a0: a.start_angle.to_radians(),
-                    a1: a.end_angle.to_radians(),
+                    a0: a.start_angle,
+                    a1: a.end_angle,
                 }),
                 EntityType::Circle(c) => Some(Geo::Circle {
                     handle: h,
@@ -949,8 +949,8 @@ fn trim_line(orig: &LineEnt, ts: &[f64], t_click: f64) -> Vec<EntityType> {
 
 /// Trim an Arc entity. Returns the surviving arc segments.
 fn trim_arc(orig: &ArcEnt, ts: &[f64], t_click: f64) -> Vec<EntityType> {
-    let a0 = orig.start_angle.to_radians();
-    let a1 = orig.end_angle.to_radians();
+    let a0 = orig.start_angle;
+    let a1 = orig.end_angle;
     let span = {
         let s = norm(a1) - norm(a0);
         if s <= 0.0 {
@@ -969,8 +969,8 @@ fn trim_arc(orig: &ArcEnt, ts: &[f64], t_click: f64) -> Vec<EntityType> {
             }
             let mut a = orig.clone();
             a.common.handle = Handle::NULL;
-            a.start_angle = angle_at(ta).to_degrees();
-            a.end_angle = angle_at(tb).to_degrees();
+            a.start_angle = angle_at(ta);
+            a.end_angle = angle_at(tb);
             Some(EntityType::Arc(a))
         })
         .collect()
@@ -1362,8 +1362,8 @@ fn entity_pts(e: &EntityType) -> Vec<[f32; 3]> {
             a.center.x,
             a.center.y,
             a.radius,
-            a.start_angle.to_radians(),
-            a.end_angle.to_radians(),
+            a.start_angle,
+            a.end_angle,
             a.center.y,
         ),
         EntityType::Ellipse(e) => {
@@ -1466,8 +1466,8 @@ impl CadCommand for TrimCommand {
             Some(EntityType::Arc(a)) => {
                 let cx = a.center.x;
                 let cy = a.center.y;
-                let a0 = a.start_angle.to_radians();
-                let a1 = a.end_angle.to_radians();
+                let a0 = a.start_angle;
+                let a1 = a.end_angle;
                 let ts = arc_seg_ts(cx, cy, a.radius, a0, a1, handle, &self.geos);
                 if ts.is_empty() {
                     return CmdResult::NeedPoint;
@@ -1630,8 +1630,8 @@ impl CadCommand for TrimCommand {
             Some(EntityType::Arc(a)) => {
                 let cx = a.center.x;
                 let cy = a.center.y;
-                let a0 = a.start_angle.to_radians();
-                let a1 = a.end_angle.to_radians();
+                let a0 = a.start_angle;
+                let a1 = a.end_angle;
                 let ts = arc_seg_ts(cx, cy, a.radius, a0, a1, handle, &self.geos);
                 if ts.is_empty() {
                     return vec![];
diff --git a/src/scene/tessellate.rs b/src/scene/tessellate.rs
index 70b53653b..fb841a02f 100644
--- a/src/scene/tessellate.rs
+++ b/src/scene/tessellate.rs
@@ -659,8 +659,11 @@ fn legacy_geometry(entity: &EntityType, world_offset: [f64; 3]) -> Geometry {
                             key_verts.push(p1);
                         }
                         acadrust::entities::BoundaryEdge::CircularArc(arc) => {
-                            let sa = (arc.start_angle as f32).to_radians();
-                            let ea = (arc.end_angle as f32).to_radians();
+                            let (sa, ea) = if arc.counter_clockwise {
+                                (arc.start_angle as f32, arc.end_angle as f32)
+                            } else {
+                                (arc.end_angle as f32, arc.start_angle as f32)
+                            };
                             let span = if ea > sa {
                                 ea - sa
                             } else {
@@ -688,8 +691,11 @@ fn legacy_geometry(entity: &EntityType, world_offset: [f64; 3]) -> Geometry {
                             let r_min = r_maj * ell.minor_axis_ratio as f32;
                             let rot = (ell.major_axis_endpoint.y as f32)
                                 .atan2(ell.major_axis_endpoint.x as f32);
-                            let sa = ell.start_angle as f32;
-                            let ea = ell.end_angle as f32;
+                            let (sa, ea) = if ell.counter_clockwise {
+                                (ell.start_angle as f32, ell.end_angle as f32)
+                            } else {
+                                (ell.end_angle as f32, ell.start_angle as f32)
+                            };
                             let span = if ea > sa {
                                 ea - sa
                             } else {