Answer:
B: 81π inches
Step-by-step explanation:
The formula for the circumference of a circle is C = πd and the formula for the area of a circle is A = πr²
- The formula for the circumference of a circle can also be written as C = 2πr since the diameter is equal to double the radius (d = 2r)
- So we need to solve for r since that is the variable we are missing in order to solve for the area
Plugging in our known values to the circumference formula we have:
- 18π = 2πr
- Then dividing both sides by 2π we have 9 = r
Now that we have solved for the radius, we can plug in this value to the area formula:
