180
pi^2
Pi is approximately equal to 3.141592652389793238462.
Pi can't be exactly expressed as a fraction, or as a decimal. It is approximately equal to 3.14159265, but for many practical calculations you may want to round it to 3.14, or to 3.1416.
pi is equal to 3.14
1/2 revolution. A complete revolution is 2 x pi radians.
1 revolution = 2 x pi radians. Therefore, 1 radian = 1 / (2 x pi) revolutions.
20 times pi There are 2 pi radians in one revolution.
One revolution = tau radians (or 2*pi radians).
There are 2π radians in one complete revolution.
180
180
Pi is not equal to 6. It is equal to 3.14159...
pi^2
Pi is approximately equal to 3.141592652389793238462.
There are very many calculations which use pi. Many of them are in geometry: areas of circles and ellipses, volumes of solids of revolution. But there are also many applications in statistics.
12/pi is equal to 12/pi, 12/3.14 (most common rounding of Pi) is about 3.822