The diagonal of a rectangle is 13 cm and one of its sides is 5 cm. Find the length of the other side and then compute the area of the rectangle in cm${}^2$.

Step-by-step solution

1. Use Pythagoras’ theorem for a rectangle: $13^2=5^2+x^2$.
2. Solve for $x$: $x^2=13^2-5^2=169-25=144$.
3. Take the square root: $x=\sqrt{144}=12$ cm.
4. Compute the area: $5\times 12=60$ cm${}^2$.

Concept tested: Pythagoras theorem for rectangle

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