Area/Circumference of Circles

Multiple Choice

A tire has a radius of 14 inches. What is its diameter?

• 14 inches

• 7 inches

• 28 inches

• 28 square inches

• 7 square inches

Circumference

• There are two fomulas for finding circumference

• C = πd

• C = 2πr

• Circumference is a little more than 3 times the diameter

What is Pi?

• the ratio of the circumference to the diameter of a circle (π= c/d)

• a greek symbol (π)

• approximately 3.14

• used when solving area and circumference of circles

Multiple Choice

The radius of the circle is 9 meters. What is the circle's circumference?

• 56.52 m

• 28.26 m

• 18 m

Multiple Choice

A cruise ship has a large, circular window with a diameter of 6 meters. Approximately what is the window's circumference?

• 18 meters

• 12 meters

• 19 meters

• 6 meters

Multiple Choice

Serena drew a circle with a circumference of 157 centimeters. What is the approximate diameter of the circle she drew?

• 1.57 cm

• 50 cm

• 15.7 cm

• 25 cm

Multiple Choice

A circular pond has a diameter of 12 feet. What is its radius?

• 12 feet

• 6 feet

• 24 feet

• 6 square feet

• 24 square feet

Fill in the Blank

Info Gap

A circle has a line segment of 26 cm.

(make sure to label the unit)

Multiple Choice

Select the correct formula for finding area of a circle

• $$2\pi r$$  

• $$\pi r^2$$  

• $$\pi d$$  

• l x w

Multiple Choice

Find the area.

• $$6.28km^2$$  

• $$18.84yd^2$$  

• $$3.14yd^2$$  

• $$12.56km^2$$  

Multiple Choice

Find the area.

• $$200.96yd$$  

• $$50.24yd^2$$  

• $$200.96yd^2$$  

• $$74.16yd^2$$  

Multiple Choice

Alex has trained his puppy, Popper, to jump through a ring. According to Alex's measurements and calculations, the ring has a diameter of 3.5 feet. What is the ring's circumference (use 3.14 for pi)?

• 11.32 ft

• 12.25 ft

• 10.99 ft

• 8.75 ft

Multiple Choice

The stained glass window is a semicircle. What is the distance around the window?

• 40.82 cm

• 66.82 cm

• 81.64 cm

• 107.64 cm

Multiple Select

How are the radius and diameter related?

Check ALL that apply

• The radius is half the diameter.

• The diameter is two times the radius.

• d = 2r

• r = d/2

Multiple Choice

What is the circumference of a 12-inch pizza?

• 37.68 inches

• 18.84 inches

• 113.04 inches

• 432.16 inches