Question

How do you find the supplement of a radian measure?

Answer 1

Two angles are, by definition, supplementary if their sum measured in degrees is `180^o`. Measured in radians, their sum should be equal to `pi` because `180^o = pi` radians.

So, if your angle is given in radians, subtract it from `pi` to get a supplementary angle in radians.

Example:
Angle `alpha` is measured in radians as `pi/3` (it's `60^o`, by the way).

It's supplementary angle is
`pi - pi/3 = (2pi)/3` (which is `120^o`)