Radians measure angles using the radius of a circle.
A full-rotation or 360 in radians is equal to the value of 2.
A half-rotation or 180 in radians is equal to the value of geometric constant (pi).
For example, the formula =DEGREES(PI()) returns 180.
PI Function
The Excel PI function returns the value of the geometric constant (pi).
The value represents a half-rotation in the radian angle system.
The constant appears in many formulas relating the circle, such as the area of a circle….
