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√(3),2x` opposite to the angles 30°, 60°, 90° respectively.

Opposite side of 90° is 9.

`2x=9`

`x=(9)/(2)`

`x=4.5`

So, opposite side of 30° is 4.5.

In a right triangle:

`\sin\theta = (Perpendicular)/(Hypotenuse)`

`\sin (30^\circ)= (4.5)/(9)`

`\sin (30^\circ)= (1)/(2)`

Therefore, the correct option is A.