# Measurements of Common Angles/Obtuse Angle

## Theorem

An obtuse angle measures $\theta$, where:

$90^\circ < \theta < 180^\circ$

or:

$\dfrac \pi 2 < \theta < \pi$

## Proof

An obtuse angle is defined to be an angle whose measure is between that of a right angle and a straight angle.

Hence the result.

$\blacksquare$