Use the formula: diameter = circumference ÷ π
Divide the circumference by 3.14159
If the circumference is C, then diameter = C / π
Example: if circumference is 31.4, diameter = 31.4 ÷ 3.14159 ≈ 10
Use the formula: diameter = circumference ÷ π
Divide the circumference by 3.14159
If the circumference is C, then diameter = C / π
Example: if circumference is 31.4, diameter = 31.4 ÷ 3.14159 ≈ 10