Question

In a right angled $△ABC,$ $\angle ABC={90}^{\circ }$, $\angle A={30}^{\circ }$. If $BC=9cm$ then $AC$?

Answer 1

In $\Delta ABC$,

$\angle ABC={90}^{\circ }$

$\angle A={30}^{\circ }$

$BC=9cm$

$AC=?$

Since, $\sin \theta =\frac{\text{Opposite side}}{\text{Hypotenuse}}$

$\Rightarrow \sin {30}^{\circ }=\frac{BC}{AC}$

$\Rightarrow \frac{1}{2}=\frac{9cm}{AC}$

$\Rightarrow AC=18cm$