To find the radius of a circle when you know the circumference, you can use the formula that relates circumference and radius. The circumference (C) of a circle is given by the formula:
C = 2πr
Where r is the radius of the circle and π (pi) is approximately 3.14159.
To find the radius, you can rearrange this formula. Start by dividing both sides of the equation by 2π:
r = C / (2π)
This means, if you have the circumference, you simply divide it by 2 times pi to get the radius. For example, if the circumference is 31.4 cm, you would calculate the radius as follows:
r = 31.4 / (2 × 3.14159)
r ≈ 5
So, the radius of the circle would be approximately 5 cm. This method works for any circle as long as you have the circumference, making it a straightforward way to determine the radius.