A right triangle has one leg measuring $5$ cm and a hypotenuse of $13$ cm. What is the length of the other leg?

Step-by-step solution

1. Use Pythagoras’ theorem: $a^2+b^2=c^2$ where $c$ is the hypotenuse.
2. Let $a=5$ cm, $c=13$ cm and solve for $b$: $b^2=13^2-5^2$.
3. Calculate the squares: $13^2=169$ and $5^2=25$.
4. Subtract: $169-25=144$.
5. Take the square root: $\sqrt{144}=12$ cm.

Concept tested: Pythagoras theorem

Published 16 October 2026 · How this solution was prepared and checked