Which set of line segments could create a right triangle?
15, 30, 35
15, 36, 39
15, 20, 29
5, 15, 30

A right triangle will satisfy Pythagoras Theorem:
c² = a² + b²; where c is the longest side.

The only segments satisfying this are
15, 36, 39

We will use the Pythagorean Theorem:
a² + b² = c²
A ) 15² + 30² = 225 + 900 = 1125 ≠ 35²
B ) 15² + 36² = 225 + 1296 = 1521 = 39² ( correct )
C ) 15² + 20² = 225 + 400 = 625 ≠ 29² 
D ) 5² + 15² = 25 + 225 = 250 ≠ 30²

B ) 15, 36, 39