An included angle is the angle made by two lines with a common vertex.
The common endpoint of 2 rays that form an angle is the vertex.
When two rays meet at a common endpoint, an angle is formed.
an angle
angle: vertex
The common end point of the sides (or arms) of an angle is the vertex of the angle.
the vertex of the angle
An angle
angle
An included angle is the angle made by two lines with a common vertex.
An angle is the union of two rays with a common endpoint.
The common endpoint of 2 rays that form an angle is the vertex.
When two rays meet at a common endpoint, an angle is formed.
an angle
40 Degrees is the most common Angle to set slides at.
I suppose you are looking for the name. The common name for a 90o angle is 'right angle'.
Two angles with two common points is commonly called a ray. An adjacent angle is an angle that has one common side and a common vertex.