Answer:
28π and 196π
10π and 25π
2500π
A = C/4π
Step-by-step explanation:
The circumference of a circle is the distance around the edge of the circle. To find the circumference, we use the formula C = 2πr. The area of the circle is the amount inside the circle and is found using A = πr². Substitute the relevant values in each situation into the formulas to find the circumference and area.
if the radius of a circle is 14 units, what is its circumference? what is its area?
Substitute r = 14.
C = 2πr = 2π(14) = 28π
A = πr² = π(14)² = 196π
if a circle has diameter 10 units, what is its circumference? what is its area?
Substitute r = 5.
C = 2πr = 2π(5) = 10π
A = πr² = π(5)² = 25π
if a circle has circumference 100π units, what is its area?
Substitute C = 100π to find the radius. Then substitute the radius into the are formula.
C = 2πr
100π=2πr
100 = 2r
50 = r
A = πr² = π(50)² = 2500π
if a circle has circumference c, what is its area in terms of c?
Cole the circumference formula for r. Then substitute the expression into the area formula.
C = 2πr
r = C / 2π
A = πr² = π(C/2π)² = πC/4π² = C/4π
