Question

Find the area of $△ABC,$ in which$AB=4$ cm, $BC=5$ cm and $\angle A={90}^{\circ }$.

• A. $4c{m}^2$
• B. $5c{m}^2$
• C. $6c{m}^2$
• D. $7c{m}^2$

Answer 1

The correct option is C $6c{m}^2$

Given: $\angle A={90}^{\circ }$

$\Rightarrow A{B}^2+A{C}^2=B{C}^2$

$\Rightarrow A{C}^2=5^2-4^2=3^2$

$\Rightarrow AC=3cm$

$\Rightarrow$ Area $=\frac{1}{2}\times AB\times AC$

$\Rightarrow$ Area $=\frac{1}{2}\times 4\times 3=6$ $c{m}^2$