Measurement of Angles
An angle is the region of the plane between two rays with common origin. The rays are called sides and have a common origin, the vertex.
An angle is positive if rotated in a counterclockwise direction and negative when rotated clockwise.
Angles are measured using the following units:
1.Sexagesimal degree (°)
If the circumference of a circle is divided into 360 equal parts, the central angle corresponding to each of its 360 parts is an angle of one degree sexagesimal, (1°).
A degree has 60 minutes (') and a minute has 60 seconds ('').
2. Radian (rad)
It is the measure of an angle whose arc is a radio.
2 rad = 360°
rad = 180°
/3 rad º