How Are Angles Measured?

To measure angles, we use a unit that is a result of dividing the distance around a circle, or the circle's circumference, by 360°. If we divide the circumference of a circle into 360 equal parts and connect two adjacent points to the center of the circle, an angle is formed whose measure is "one degree."

In the circle O, points R and S are adjacent points after dividing the circle’s circumference into 360 equal parts.  Lines RO and SO are drawn. They form the angle ROS. The measure of angle ROS is one degree. Look at the diagram below. If the openness of angle RQT is 35 times the openness of angle ROS, then we say that angle RQT measures 35 degrees. A degree measure is denoted by the sign " ° " at the top corner of the measure number. For example, the measure of the angle RQT is written as 35°.

To denote the measure of an angle, we use the symbol m before the name of the angle, for example, m and m