A right‑angled triangle has legs of lengths 8 cm and 15 cm. Using Heron's formula, compute its area.

Step-by-step solution

1. Find the hypotenuse by Pythagoras: $\sqrt{8^2+15^2}=17$ cm.
2. Compute the semiperimeter: $s=\frac{8+15+17}{2}=20$.
3. Compute $s-a$, $s-b$, $s-c$: $20-8=12$, $20-15=5$, $20-17=3$.
4. Multiply: $20\times 12\times 5\times 3=3600$.
5. Take the square root: $\sqrt{3600}=60$.
6. Hence the area is $60{\text{cm}}^2$.

Concept tested: Area of triangle using Heron's formula

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