Circle: Circumference
How to find the circumference of a circle: 2 formulas, 2 examples, and their solutions.
FormulaRadius
C = 2πr
C: Circumference of a circle
r: Radius
Exampler = 5, C = ?
Solution
Solution (Detail)
r = 5
So use C = 2πr.
C = 2π⋅5
2π⋅5 = 10π
So 10π is the answer.
FormulaDiameter
C = πd
d: Diameter
ExampleDiameter: 13, C = ?
Solution
Solution (Detail)
d = 13
So use C = πd.
C = π⋅13
π⋅13 = 13π
So 13π is the answer.