Which of the following sets of numbers is a pythagorean triple?

77, 35, 112
70, 35, 78
75, 36, 83
77, 36, 85

In order to identify if the given set is a Pythagorean triple, add the square of the two smaller numbers. The sum should be equal to the square of the remaining number.

(1)      77² + 35² = 7154 ;       112² = 12544  ;   Not Equal
(2)      70² + 35² = 6125 ;        78² = 6084     ;   Not Equal
(3)      75² + 36² = 6921 ;        83² = 6889     ;   Not Equal
(4)      77² + 36² = 7225 ;        85² = 7225     ;     Equal

The answer is the fourth choice. 

Where are the functions?

Ithink if im not mistaking b is -3 but im not a 100% sude