A circle only has one angle. It is named a full angle and measures 360 degrees or 2 pi radians.
Pi is a mathematical constant. It is the ratio of the circle's circumference to its diameter. Pi is estimated as 3.14159 in mathematical calculations.
The angle of the circle is taken from its center. The center is the equidistant point from all the circle's points. An angle is formed from the circle's center by two radius lines. Radius refers to the line from the circle's center to any end point on the circle's circumference. If two radius lines combine and become one line, the angle is 360 degrees.