The angle is geometric shape formed by joining of two lines; these lines are called the sides of the angle, and they share the endpoint. The meeting of the two points is called the vertex of the angle. The angle is commonly represented by this symbol (∠).

The degree sign (°) is used as the unit of measurement of the angle.

Types of angles: right angle exactly equals 90°, an acute angle is less than 90°. An obtuse angle which measures between 90° and 180°, straight angle equals exactly 180°, reflex angle measures between 180° and 360° and finally the full angle equals 360°.