To find the diameter of a circle divide its circumference by pi
Chat with our AI personalities
C = pi*d
By algebraic rearrangement
d = C /pi
NB pi is a mathematical constant with the value of 3.141592654....
For school work it is approximated to 3.14.
If you know the circumference, the ration of the diameter to the circumference is π, so diameter = circumference/π If you have the radius, diameter = 2 x radius
Diameter = circumference/pi
circumference of a circle = pi * diameter.
If you know the circumference, use the formula for circumference (C=pi*diameter), but rearrange it to get Diameter= circumference/pi. Then just sub in values.
you multiply the diameter by pi.