added circular_sector

src/circual_sector.scad

@@ -0,0 +1,16 @@
+module circular_sector(radius, angles, fn = 24) {
+    r = radius / cos(180 / fn);
+    step = -360 / fn;
+
+    points = concat([[0, 0]],
+        [for(a = [angles[0] : step : angles[1] - 360]) 
+            [r * cos(a), r * sin(a)]
+        ],
+        [[r * cos(angles[1]), r * sin(angles[1])]]
+    );
+
+    difference() {
+        circle(radius, $fn = fn);
+        polygon(points);
+    }
+}