it depends it can be acute(less than 90 degrees (more than 90 degrees), or right(90 degrees)
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
'Angle' is a common noun.
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'.