Application of Circles

A circular mat has a diameter of 50 in. Lily wants to sew a decorative braid around the mat. How many inches of braid does she need?

A gardener is hired to cut the grass in a circular field having a diameter of 25 ft. If he cuts at an average of 60 square feet per hour, how long will it take him to finish the job?

• 8.18 hours

• 32.72 hours

• 1.31 hours

• 2.62 hours

The diameter of a circular fountain in a city park is 28 feet. A sidewalk that is 3.5 feet will be built around the fountain as shown in the figure. What is the area of the sidewalk?

A metalworker cuts out a large semicircle with a diameter of 28 centimeters. Then the metalworker cuts a smaller semicircle out of the larger one and removes it as shown in the figure. What is the area of the shape left after the smaller semicircle is removed?

The diameter of a bicycle wheel is 60 centimeters. How far does the wheel travel when it makes 35 revolutions?