Solving Problems Involving 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

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

The circumference of a circle is 36.31 meters. What is the approximate length of the radius? Use 3.14 for π.

• 3 m

• 4 m

• 5 m

• 6 m

The circumference of a circle is 18.41 feet. What is the approximate length of the radius? Use 3.14 for π.

• 3 ft

• 5 ft

• 7 ft

• 8 ft

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.

Mrs VanSciver bought a circular rug. The radius of the rug was 2.5 feet. How does the diameter of the rug compare to the radius? Use 3.14 for π.

• The diameter of the rug is twice the radius.

• The radius is twice the circumference.

• The diameter of the rug is half the radius.

• The diameter is twice the circumference.

Mr. Blain designed a circular walkway in front of his house. The diameter of the walkway is about 6 feet long. How many square feet of bricks will he need to buy? Use 3.14 for π.

• 18.84 square feet

• 113.04 square feet

• 9.42 square feet

• 28.26 square feet

The circle represents a tablecloth that Angie bought. She wants to sew fringe along the edge of the tablecloth. How many of fringe does she need to buy? Use 3.14 for π.

• 12.4 ft

• 7.9 ft

• 19.6 ft

• 15.7 ft

Alejandra is making a tablecloth. Her table has a 7 foot diameter. How many square feet of material does she need to use? Use 3.14 for π.

• 10.9 square feet

• 153.9 square feet

• 38.5 square feet

• 21.9 square feet