All you have to do is see if they are all true statements.
a. 8+15 should be bigger than 17
15+17 should be bigger than 8
17+8 should be bigger than 15
a. is a right triangle
b.11+5 should be bigger than 8
8+11 should be bigger than 5
8+5 should be bigger than 11
b. is a right triangle.
I hope that helped. I’m using a different technique and I hope it’s correct.