Added new area calculators (#428)

Maths/Area.js

@@ -0,0 +1,99 @@
+/*
+  Calculate the area of various shapes
+
+  Calculate the Surface Area of a Cube.
+  Example: surfaceAreaCube(1) will return 6
+  More about: https://en.wikipedia.org/wiki/Area#Surface_area
+ */
+const surfaceAreaCube = (sideLength) => {
+  validateNumericParam(sideLength, 'sideLength')
+  return (6.0 * sideLength ** 2.0)
+}
+
+/*
+  Calculate the Surface Area of a Sphere.
+  Wikipedia reference: https://en.wikipedia.org/wiki/Sphere
+  return 4 * pi * r^2
+*/
+const surfaceAreaSphere = (radius) => {
+  validateNumericParam(radius, 'radius')
+  return (4.0 * Math.PI * radius ** 2.0)
+}
+
+/*
+  Calculate the area of a rectangle
+  Wikipedia reference: https://en.wikipedia.org/wiki/Area#Quadrilateral_area
+  return width * length
+*/
+const areaRectangle = (length, width) => {
+  validateNumericParam(length, 'Length')
+  validateNumericParam(width, 'Width')
+  return (width * length)
+}
+
+/*
+  Calculate the area of a square
+*/
+const areaSquare = (sideLength) => {
+  validateNumericParam(sideLength, 'side length')
+  return (sideLength ** 2)
+}
+
+/*
+  Calculate the area of a triangle
+  Wikipedia reference: https://en.wikipedia.org/wiki/Area#Triangle_area
+  return base * height / 2
+*/
+const areaTriangle = (base, height) => {
+  validateNumericParam(base, 'Base')
+  validateNumericParam(height, 'Height')
+  return (base * height) / 2.0
+}
+
+/*
+  Calculate the area of a parallelogram
+  Wikipedia reference: https://en.wikipedia.org/wiki/Area#Dissection,_parallelograms,_and_triangles
+*/
+const areaParallelogram = (base, height) => {
+  validateNumericParam(base, 'Base')
+  validateNumericParam(height, 'Height')
+  return (base * height)
+}
+
+/*
+  Calculate the area of a trapezium
+*/
+const areaTrapezium = (base1, base2, height) => {
+  validateNumericParam(base1, 'Base One')
+  validateNumericParam(base2, 'Base Two')
+  validateNumericParam(height, 'Height')
+  return 1.0 / 2.0 * (base1 + base2) * height
+}
+
+/*
+  Calculate the area of a circle
+*/
+const areaCircle = (radius) => {
+  validateNumericParam(radius, 'Radius')
+  return (Math.PI * radius ** 2)
+}
+
+/*
+  Calculate the area of a rhombus
+  Wikipedia reference: https://en.wikipedia.org/wiki/Rhombus
+*/
+const areaRhombus = (diagonal1, diagonal2) => {
+  validateNumericParam(diagonal1, 'diagonal one')
+  validateNumericParam(diagonal2, 'diagonal two')
+  return (1 / 2 * diagonal1 * diagonal2)
+}
+
+const validateNumericParam = (param, paramName = 'param') => {
+  if (typeof param !== 'number') {
+    throw new TypeError('The ' + paramName + ' should be type Number')
+  } else if (param < 0) {
+    throw new Error('The ' + paramName + ' only accepts non-negative values')
+  }
+}
+
+export { surfaceAreaCube, surfaceAreaSphere, areaRectangle, areaSquare, areaTriangle, areaParallelogram, areaTrapezium, areaCircle, areaRhombus }