Circumference and Area of Circles

A circle has a diameter of 4.5 cm. A larger circle has a diameter of 24 cm. What is the approximate difference in the circumferences of the two circles?

• 19.5 cm

• 28.5 cm

• 61 cm

• 90 cm

A circular track with a diameter of 60 meters is shown. Shaleah walked around the track 4 times. Approximately how many meters did she walk?

• 377

• 2826

• 754

• 11,304

Lily is making party favors by placing a circular disk in the bottom of a plastic bag. Each disk has a diameter of 6 centimeters. What is the area of the disk to the nearest hundredth of square centimeter?

Use 3.14 for 𝜋.

• 18.84 cm²

• 28.26 cm²

• 91.06 cm²

• 113.04 cm²

Jayne has a very large circular lollipop that has a circumference of 25.12 inches. What would the area of Jayne’s lollipop be?

• 50.24 in.²

• 200.96 in²

• 12.56 in. ²

• 78.88 in^.2

A circular mirror has a 2 inch frame around it. The mirror itself is 8 inches in diameter. What is the area of the frame? Use 3.14 for pi.

The circumference of a circle is 28.26 cm. What is closest to the area of the circle.

• 254.34 cm²

• 14.13 cm²

• 63.6 cm²

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

Find the circumference of each circle when given the area.
area = 64π mi²

• C =  32 mi

• C = 42.5 mi

• C = 50.3 mi

• C = 64  mi

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

Identify the parts of the circle and show how you would find the area and circumference.

Groups:

(a) radius

,

(b) diameter

,

(c) circumference

,

(d) area