Find the area of a triangle whose two sides are $a=7\text{cm}$ and $b=9\text{cm}$ and the included angle $C=30^{\circ }$.

Step-by-step solution

1. Write the area formula for two sides and the included angle: $\text{Area}=\frac{1}{2}ab\sin C$.
2. Substitute the given values $a=7$, $b=9$, $C=30^{\circ }$ into the formula.
3. Evaluate $\sin 30^{\circ }=0.5$.
4. Compute $\text{Area}=\frac{1}{2}\times 7\times 9\times 0.5=15.75$ cm${}^2$.
5. State the final answer.

Concept tested: Area of triangle (SAS)

Published 22 August 2026 · How this solution was prepared and checked

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