# 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

py

```
def shape_area(n):
return (n**2 + (n-1)**2)
print(shape_area(3))
```

js

```
function shapeArea(n) {
return n ** 2 + (n - 1) ** 2;
}
console.log(shapeArea(3));
```