Question

Given the diagram below, what is sin (30•)?

Answer 1

Given:

The figure of a right triangle.

To find:

The value of $\sin(30^\circ)$.

Solution:

We know that, the sides of 30°-60°-90° right triangle are $x,x\sqrt{3},2x$ opposite to the angles 30°, 60°, 90° respectively.

Opposite side of 90° is 9.

$2x=9$

$x=\dfrac{9}{2}$

$x=4.5$

So, opposite side of 30° is 4.5.

In a right triangle:

$\sin\theta = \dfrac{Perpendicular}{Hypotenuse}$

$\sin (30^\circ)= \dfrac{4.5}{9}$

$\sin (30^\circ)= \dfrac{1}{2}$

Therefore, the correct option is A.