Real-World Problems: 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 feet did the Ferris wheel rotate with one complete turn? (Think of 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 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.

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