Area and Circumference of Circles

If my diameter is 19 inches, what is my radius?

• 38 inches
• 9.5 inches
• 59.66 inches
• 119.32 inches

If my radius is 10ft, what is my diameter?

• 20ft
• 5ft
• 31.4ft
• 62.8ft

what is the circumference of this circle ?

• 3.14 cm 
• 37.68 cm
• 24 cm
• 68.4 cm

Elsie bought a circular rug that is 9 feet in diameter. What is the circumference of the rug rounded to the nearest tenth of a foot?

• 4.5 feet

• 14.1 feet

• 28.3 feet

• 56.5 feet

Landon left a garbage can on the lawn and the grass underneath it died. The diameter of the can is 50 centimeters. What is the area of the grass that died? Use 3.14 for pi.

• 53.14 centimeters

• 157 centimeters

• 15.9 centimeters

Circle A has diameter d and a radius r.

What is the result of dividing the circumference by the diameter?

• 2r

• 2

• $\pi$

• $2\pi$

A wheel has a diameter of 30 centimeters. In one rotation of the wheel, how much distance is covered? Use 3.14 for pi.

• 94.2 cm

• 33.14 cm

• 30 cm

• 90 cm

A circle has a diameter of 12 inches. What is the area of the circle. Use 3.14 for pi.

Remember, to find the radius, divide the diameter by 2.

• 37.68 inches²

• 18.84 inches²

• 113.04 inches²

Which ratio defines pi?

• $\frac{diameter}{circumference}$

• $\frac{radius}{circumference}$

• $\frac{circumference}{diameter}$

• $\frac{circumference}{radius}$

Kevin is buying a cover for his circular swimming pool. If the diameter is 22 feet, how much material will it take to cover the pool? Use 3.14 for pi.

• 69.08 ft²

• 379.94 ft²

• 34.54 ft²