The area of a circle is 16π cm2. What is the circle's circumference?
2π cm
4π cm
8π cm
16π cm
To find the circumference of a circle, you can use the formula C = 2πr, where C represents the circumference and r represents the radius of the circle.
In this case, we need to find the circumference of a circle with an area of 16π cm^2.
To find the radius, we can use the formula for the area of a circle, A = πr^2. Substituting the given area, we have:
16π = πr^2
We can simplify this equation by canceling out π from both sides:
16 = r^2
To solve for r, we need to take the square root of both sides:
√16 = √r^2
4 = r
Now that we know the radius is 4 cm, we can calculate the circumference using the formula C = 2πr:
C = 2π(4)
C = 8π cm
Therefore, the circumference of the circle is 8π cm. The correct answer is 8π cm.
The radius must be 4 cm.
C = pi * diameter