JavaScript Algorithm: Sum of Polygon Angles

Finding the sum of internal angles in a polygon

Photo by George Pagan III on Unsplash

Today, we write a function called sumPolygon that will accept one integer, n, as an argument.

You are given an n-sided regular polygon. The goal of the function is to calculate and return the total sum of internal angles. We are not going to go into mathematical detail on finding polygon angles, but we do have a formula to help you find the sum:

(n - 2) * 180

Here are some examples:

sumPolygon(3) // 180

sumPolygon(4) // 360

sumPolygon(6) // 720

Using the examples, we get our result by plugging n into our formula above:

(3 - 2) * 180 = 180
(4 - 2) * 180 = 360
(6 - 2) * 180 = 720

To write our function, all we have to do is return the result of the formula.

return (n - 2) * 180

Here is the rest of the code:

function sumPolygon(n){
    return (n - 2) * 180;
}

If you find this algorithm helpful, check out my other JavaScript algorithm solution articles: