Area and Circumference of Circles

An architect is making a plan for a new circular playground. If the picture below is the playground, how much fencing needs to go up to keep the kids in the circle? Use 3.14 for π.

• 3,215 m

• 201 m

• 402 m

• 100 m

A bicycle trail in the shape of a circle has a diameter of 3 miles. Kiersty biked around the trail 4 times. About how far did Kiersty bike? Use 3.14 for π.

• 38 miles

• 40 miles

• 35 miles

• 33 miles

The radius of a birthday cake is 4 inches. Icing will decorate the circumference of the cake. What procedure can be used to find the approximate circumference of the cake? Use 3.14 for π.

• Multiply 4 by 3.14.

• Multiply 4 by 2, and then multiply the product by 3.14.

• Multiply 4 by 4, and then multiply the product by 3.14.

• Divide 4 by 2, and then multiply the quotient by 3.14.

What is the formula to calculate the circumference of a circle?

A circular garden has a radius of 14 meters. What is the length of the fence required to enclose it?

Match the following definitions to the terms:

• The distance around a circle

• Units of area

• feet, cm, inches

• Units of circumference

• square units (units²)

• Area of a circle

• How much space a circle takes up

• Circumference of a circle

What is the circumference of a circle with a diameter of 8 inches?

The first Ferris wheel was built in 1893 in Chicago. Its diameter was 250 feet. How many feel did the Ferris wheel rotate with one complete turn? (Think the outside measurement of the circle.) Use 3.14 for π.

• 785 ft

• 390 ft

• 912 ft

• 543 ft