Measurements of Common Angles/Acute Angle

Measurement of Acute Angle
An acute angle is defined to be an angle whose measure is between that of a zero angle and a right angle.

As a zero angle measures $0$ and a right angle measures $90^\circ$ or $\dfrac \pi 2$, it follows that an acute angle measures $\theta$, where:
 * $0^\circ < \theta < 90^\circ$

or:
 * $0 < \theta < \dfrac \pi 2$