Question

In $△ABC,\angle B={90}^{\circ },AB=24cm$ and $BC=7cm$.

Then, $\cos A=$

• A. $\frac{7}{24}$
• B. $\frac{7}{25}$
• C. $\frac{24}{25}$
• D. None of these

Answer 1

The correct option is C $\frac{24}{25}$

$A{C}^2=A{B}^2+B{C}^2={24}^2+7^2=625$

$\therefore AC=25$

$\therefore \cos A=\frac{AB}{AC}=\frac{24}{25}$