A rectangular window has a diagonal of 10 cm and one side of 6 cm. Find the length of the other side and then find the perimeter of the window in cm.

Step-by-step solution

1. Use Pythagoras theorem $a^2+b^2=d^2$ for a rectangle, where $d$ is the diagonal.
2. Substitute $a=6$ cm and $d=10$ cm: $6^2+b^2=10^2$.
3. Solve for $b^2$: $b^2=100-36=64$.
4. Take square root to get $b=8$ cm. Compute perimeter $P=2(a+b)=2(6+8)=28$ cm.
5. The other side is $8$ cm and the perimeter is $28$ cm.

Concept tested: Finding missing side and perimeter of a rectangle

Published 13 October 2026 · How this solution was prepared and checked