In a large field, a circle with an area of 144_π_ square meters is drawn out. Starting at the center of the circle, a groundskeeper mows in a straight line to the circle's edge. He then turns and mows ¼ of the way around the circle before turning again and mowing another straight line back to the center. What is the length, in meters, of the path the groundskeeper mowed?

Two concentric circles have circumferences of 4π and 10π. What is the difference of the radii of the two circles?

A circle has an area of 36π inches. What is the radius of the circle, in inches?

Circle X is divided into 3 sections: A, B, and C. The 3 sections are equal in area. If the area of section C is 12π, what is the radius of the circle?

Circle X

In the figure above, rectangle ABCD has a perimeter of 40. If the shaded region is a semicircle with an area of 18π, then what is the area of the unshaded region?

A certain circle has a circumference (in units) that is two times the area (in units squared). What is the radius of the circle?

Consider a circle centered at the origin with a circumference of . What is the x value when y = 3? Round your answer to the hundreths place.

A circle has an area of . What is the radius of the circle, in inches?

The specifications of an official NBA basketball are that it must be 29.5 inches in circumference and weigh 22 ounces. What is the approximate radius of the basketball?

A circle with center (8, **–**5) is tangent to the y-axis in the standard (x,y) coordinate plane. What is the radius of this circle?