Shape Area

Below we will define an n-interesting polygon. Your task is to find the area of a polygon for a given n.

A 1-interesting polygon is just a square with a side of length 1. An n-interesting polygon is obtained by taking the n - 1-interesting polygon and appending 1-interesting polygons to its rim, side by side. You can see the 1-, 2-, 3- and 4-interesting polygons in the picture below.

Image Credit: CodeSignal

Example

• For n = 2, the output should be

  shape_area(n) = 5

• For n = 3, the output should be

  shape_area(n) = 13

Solution

PYTHON

def shape_area(n):
    return (n**2 + (n-1)**2)


print(shape_area(3))

JAVASCRIPT

function shapeArea(n) {
  return n ** 2 + (n - 1) ** 2;
}

console.log(shapeArea(3));