Question

In the given right angle triangle ABC, if $\alpha ={30}^{\circ }$ and AC = 10 cm then the side BC would be___ cm

Answer 1

Trigonometric ratio ,

$sin\alpha =\frac{\text{opposite side}}{\text{hypotenuse side}}=\frac{BC}{AC}$
$sin\alpha =\frac{1}{2}when\alpha ={30}^{\circ }$
Thus, $\frac{BC}{AC}=\frac{1}{2}$
$BC=5cm$