Add an algorithm to find length of an arc and area of the sector formed by an arc of a circle

Maths/CircularArc.js

@@ -0,0 +1,41 @@
+/**
+ * @function degreesToRadians
+ * @description convert from degrees to radians
+ * @param {Integer} angle in degrees
+ * @return {Integer} degrees * pi / 180
+ * @see https://en.wikipedia.org/wiki/Degree_(angle)
+ * @example degreesToRadians(45) = 0.7853981633974483
+ */
+function degreesToRadians (degrees) {
+  return degrees * Math.PI / 180
+}
+
+/**
+   * @function circularArcLength
+   * @description calculate the length of a circular arc
+   * @param {Integer} radius
+   * @param {Integer} degrees
+   * @returns {Integer} radius * angle_in_radians
+   * @see https://en.wikipedia.org/wiki/Circular_arc
+   * @example circularArcLength(3, 45) = 2.356194490192345
+   */
+function circularArcLength (radius, degrees) {
+  return radius * degreesToRadians(degrees)
+}
+/**
+   * @function circularArcArea
+   * @description calculate the area of the sector formed by an arc
+   * @param {Integer} radius
+   * @param {Integer} degrees
+   * @returns {Integer} 0.5 * r * r * angle_in_radians
+   * @see https://en.wikipedia.org/wiki/Circular_arc
+   * @example circularArcArea(3,45) = 3.5342917352885173
+   */
+function circularArcArea (radius, degrees) {
+  return Math.pow(radius, 2) * degreesToRadians(degrees) / 2
+}
+
+export {
+  circularArcLength,
+  circularArcArea
+}