# Estimating angles

To estimate the size of an angle, try thinking in terms of counting in quarter turns, or right angles.

For example, the angle in the following diagram is acute - the line turns less than a right angle to get to the other line, so it must be between and .

The angle in the following diagram is a reflex angle. The line turns through more than two right angles, but less than three right angles, so is between and .

To be even more accurate think in terms of angles.

This angle lies somewhere between and , but seems slightly closer to , so you could estimate that it is .