Which set of integers is not a Pythagorean triple?

A.

9, 40, 41

B.

11, 60, 61

C.

15, 18, 21

D.

20, 21, 29

The answer is c

a pythagorean tripple refers to a set of numbers that fits the equation a^2 + b^2 = c^2

we know that c must be the biggest number and it doesnt matter which of the other ones is a or b

therefore we substitute the options into the equation and tge one that doesnt work is c 15, 18, 21