algorithm class: circle (TheAlgorithms#1252)

Geometry/Circle.js

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+/**
+ * This class represents a circle and can calculate it's perimeter and area
+ * https://en.wikipedia.org/wiki/Circle
+ * @constructor
+ * @param {number} radius - The radius of the circule.
+ */
+export default class Circle {
+  constructor (radius) {
+    this.radius = radius
+  }
+
+  perimeter = () => {
+    return this.radius * 2 * Math.PI
+  }
+
+  area = () => {
+    return Math.pow(this.radius, 2) * Math.PI
+  }
+}

Geometry/Test/Circle.test.js

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+import Circle from '../Circle'
+
+const circle = new Circle(3)
+
+test('The area of a circle with radius equal to 3', () => {
+  expect(parseFloat(circle.area().toFixed(2))).toEqual(28.27)
+})
+
+test('The perimeter of a circle with radius equal to 3', () => {
+  expect(parseFloat(circle.perimeter().toFixed(2))).toEqual(18.85)
+})