To find the area of a circle when you have its circumference, you can follow these steps:
- Understand the relationship between circumference and radius: The formula for the circumference (C) of a circle is given by:
- Rearrange the formula to find the radius: You can rearrange the circumference formula to solve for the radius:
- Calculate the area: The formula for the area (A) of a circle is:
- Put it into practice: For instance, if the circumference of the circle is 31.4 units, you can calculate the area:
C = 2 × π × r
where r is the radius of the circle.
r = C / (2 × π)
Now, you have the radius in terms of circumference.
A = π × r2
Now, substitute the radius you found out in the previous step:
A = π × (C / (2 × π))2
When you simplify this equation, it will look like:
A = (C2) / (4 × π)
So, now you have a direct formula for the area in terms of the circumference of the circle.
A = (31.42) / (4 × π) ≈ 78.54
Thus, the area of the circle would be approximately 78.54 square units.
In summary, the area of a circle can easily be calculated from its circumference by first finding the radius and then using the area formula. This method shows the fundamental relationship between the two measurements!