Answer: 20
Explanation:
It's like the 3-4-5 rule. You have other like rules, for ex:
3-4-5
6-8-10
9-12-15
12-16-20
15-20-25
All of those numbers represents each side of the triangle, because when you split a square in half, you get a triangle. So, you have 3 sides, 1 side measures 12 and another 16, so that leaves the last side to measure 20.
Hope this helps you out!! (:
