algorithm: volume of sphere (#1249)

* Added sphere volume

* Fixed indentation

* Added PR Suggestions

Geometry/Sphere.js

@@ -0,0 +1,19 @@
+/**
+ * This class represents a sphere and can calculate its volume and surface area
+ * @constructor
+ * @param {number} radius - The radius of the sphere
+ * @see https://en.wikipedia.org/wiki/Sphere
+ */
+export default class Sphere {
+  constructor (radius) {
+    this.radius = radius
+  }
+
+  volume = () => {
+    return Math.pow(this.radius, 3) * Math.PI * 4 / 3
+  }
+
+  surfaceArea = () => {
+    return Math.pow(this.radius, 2) * Math.PI * 4
+  }
+}