Mathematics

Problem

Which one of the following relations correctly identifies that a triangle having sides

p,\,q,\,r

(with

r

the longest) is a right triangle? a)

p^{2}=q^{2}+r^{2}

2r^{2}=p^{2}+q^{2}

r^{2}=p^{2}+q^{2}

r^{2}=p^{2}-q^{2}