# Law of Sines

## Angles in a generic triangle

The "Law of Sines" can be used to calculate the angles of a triangle.

The "Law of Sines" can be expressed as

*a / sin A = b / sin B = c / sin C ^{} (1)*

*where *

*a, b and c = length of sides in triangle (m, ft ...)*

*A, B and C = angles in the triangle (degrees)*

### Law of Sines Calculator

*a (m, ft ....)*

*b (m, ft ....)*

*A (degrees)*

This expression can also be handy:

*sin 1/2 A = ((s - b)(s - c) / (b c)) ^{1/2} (2)*

*where *

*s = 1/2 (a + b + c)*