Question

a triangle has sides of lengths 8,15, and 17is it a right triangle?

Answer 1

Yes. Either memorize your pythagorean triples (3,4,5; 5, 12, 13...) there are an infinite amount though, you really only need to know 3, 4, 5.

To solve otherwise, test it using the pythagorean theorem (a^2+b^2=c^2). It works out correctly, therefore it is right. If you had 8, 15, and 16 and tried the same thing, you would end up with a false statement

Answer 2

the last number is 17 and not 16

ATTENTION !!!