Question #N549

A triangle has sides of length 5, 12, and 13. Is this triangle a right triangle? Explain your reasoning.
A. Yes, because $5^2 + 12^2 = 13^2$.
B. Yes, because $5 + 12 = 13$.
C. No, because $5^2 + 12^2 \neq 13^2$.
D. No, because $5 + 12 \neq 13$.