Radius & Diameter
The diameter is 10 inches. Find the radius.
What is 5 inches.
A circle has a diameter of 12.5 inches. What is the circumference in terms of pi?
What is 12.5pi inches? or 39.25
The relationship between diameter and radius
What is d= 2r or r = d/2
A bicycle wheel has a radius of 1 foot. What is the diameter?
2 ft
The diameter is 25 feet. Find the radius.
What is 12.5 feet.
A circle has a diameter of 25 inches. What is the circumference rounded correctly to 2 decimals (no pi in the answer)?
What is 78.54 inches
2*pi*r
A large Jeep has a tire with a radius of 18 inches. Find the circumference of the wheel.
What is 36pi?
or 113.04
The circumference of the circle is 18pi inches. Find the radius.
What is 9 inches.
A circle has a radius of 50 miles. What is the area of the circle TO THE NEAREST MILE?
What is 7854 miles squared.
Area of a circle
What is pi*r^2?
Matt is learning to drive a car. The steering wheel in his car has a radius of 9 inches. His instructor says "Place your hands at 10 and 2." (1/3 of the circle) What is the area of the circle formed in terms of pi?
What is 27pi inches.
or 84.78 inches
The area of this circle is 25pi inches squared. Find the radius.
What is 5 inches.
A circle has a diameter of 16. Find the area in terms of pi.
What is 4(y^2)pi
Finding radius when given circumference
C/2pi = r
John owns a circular pool in his back yard. If he swims around the pool, he swims 30pi meters. What is the radius of this circle?
What is 15 meters.
A circle has an area of 256pi cm squared. Find the diameter.
What is 32cm
A circle has a circumference of 6pi. What is the area?
What is 9pi? or 28.26
Finding the area of a circle when given diameter
What is (d/2)^2*pi = A
A circle has a diameter of 28 inches. What is the area of a quarter of the circle? You must give your answer as either a whole number or a decimal
What is 154? (153.86)