Question

Which of these four sets of side lengths will form a right triangle?

Answer 1

Your answer will be number 4
You can simply check by
The sum of the square of first two number should be equal to the square of third number to form a right angled triangle (simply use Pythagorean’s theorem)

For example in set four

12²+16²=20²
144+256=400
400=400
So it is a right angled triangle

Hope it helps : )