is formed when two rays meet a common endpoint.

If the terminal side of an angle in standard positions coincide with one of the axes such as 90⁰, 180⁰,270⁰ or360⁰,it is called a _______________. 

The ray on the positive x-axis.

Angle that have the same terminal side.

The positive acute angle formed between the terminal side of this angel and the x-axis

If the terminal side of the angle rotates in a counterclockwise direction, we say that the angle has a negative measurement.

Radian is the measure of an angle in standard position whose terminal side intercepts an arc of length r

The point forming the angle are called its side

When the vertex is at the origin and the initial side is at the positive x-axis, we say that the angle is in standard position

When it rotates in a clockwise direction, the angle measurement is positive.