Use the formula: C = 2πr
Or use the formula: C = πd
C = circumference
r = radius
d = diameter
Multiply 2 by π and the radius
Or multiply π by the diameter
Use π ≈ 3.14 if needed
Keep the answer in the same units as the radius or diameter
Use the formula: C = 2πr
Or use the formula: C = πd
C = circumference
r = radius
d = diameter
Multiply 2 by π and the radius
Or multiply π by the diameter
Use π ≈ 3.14 if needed
Keep the answer in the same units as the radius or diameter