In a right‑angled triangle, the legs are 9 cm and 12 cm. What is the length of the hypotenuse?

Step-by-step solution

1. Apply Pythagoras theorem: $a^2+b^2=c^2$.
2. Compute $9^2+12^2=81+144=225$.
3. Take the square root: $c=\sqrt{225}=15$.
4. Thus the hypotenuse is 15 cm.

Concept tested: Right‑triangle hypotenuse

Published 10 October 2026 · How this solution was prepared and checked