Angle is formed between two rays with a common end point.
The common end point is called vertex of the angle
and the rays are called arms of the angle.
How do we name the angle?
Suppose the angle is
We can call it
Symbol of angle → ∠
Interior and Exterior of an angle
Let us take the angle
X, Y is in interior of ∠ABC
Z is on ∠ABC
P, Q is in exterior of ∠ABC