Question

The lengths of the sides of four triangles are given. Which triangle is a right triangle?
6in., 6 in., 6 in.
8in., 9in., 10 in.
5in., 9in., 12in.
9in., 12in., 15in

Answer 1

How does this work how do i get help with the problem posted

Answer 2

For a right triangle pythagoreans theorem must apply. \[a ^{2}+b ^{2}=c ^{2}\]
If you plug in the numbers the last one is the only one that works with.
Proof:
\[9^{2}+12^{2}=225=15^{2}\]