 # Sin 30 Formula

Sin 30 Formula: Sin 30 degrees is equal to cos 60 degrees. The value of sin 30 degrees is 1/2.

What is the formula for sin 30?

In an equilateral triangle, the measure of each triangle is 60° and all the sides are equal.

Let’s assume all the side to be of 2 cm. After bisecting the angle, it would become 30° and length of the side will be ½ (the side opposite to the angle 60 degrees which equal to 1), this way we get sine 30° as ½.

In a right angle triangle, one of the angles is 90°. To find the value of various trigonometric functions for different angles, we refer to the trigonometry table.

## Trigonometry Ratio Table for Sin 30 degree formula

 Trigonometry Ratio Table Angles (In Degrees) 0° 30° 45° 60° 90° Angles (In Radians) 0 π/6 π/4 π/3 π/2 sin 0 1/2 1/√2 √3/2 1 cos 1 √3/2 1/√2 1/2 0 tan 0 1/√3 1 √3 Not Defined cot Not Defined √3 1 1/√3 0 csc Not Defined 2 √2 2/√3 1 sec 1 2/√3 √2 2 Not Defined

## What is the Value of Sin 30°?

The value of sin 30 degrees can be found with the help of the above trigonometric table.

 Sin 30° = 1/2

## Solved Examples

Example 1: Find the value of sin 30° + 2 cos 60°.

Solution:
sin 30° + 2 cos 60°
= sin 30° + 2 cos (90° – 30°)
= sin 30° + 2 sin 30°
= 3 sin 30°
= 3(½)
= 3/2

Example 2: Simplify: 2 sin 30°/(1 – sin230°)

Solution:
2 sin 30°/(1 – sin230°)
= 2 (½)/[1 – (½)2] = 1/[1 – ¼] = 1/(¾)
= 4/3

Example 3: Find the value of 5 sin 30°/7 cos 60°.

Solution:
5 sin 30°/7 cos 60°
= 5 sin 30°/ 7 cos (90° – 30°)
= (5/7) (sin 30°/sin 30°)
= (5/7)(1)
= 5/7