1. ## Convex polygons

What is the quickest way to solve this?

If a convex polygon has n sides and 25n diagonals, find the value of n.

Thanks!

2. Hmm...I think you would solve it like this

$\frac{n(n-3)}{2}=25n$

Solve for n.

I got $n = 53$ when solving. I hope that's right sorry if its not.