Using Formulas for Circumference

Area and Circumference of Circles

by Holly Wilder

​Circumference

​The distance around the circle.

​To find circumference you use Pi! Pi is the constant of proportionality that relates diamter to circumference.

Multiple Choice

What is the circumference of a circle with a diameter of 19.1 ft? 

• 60.00 ft
• 35.17 ft
• 28.67 ft
• 47.17 ft

Multiple Choice

The diameter of a truck wheel is 56.5 inches. What is the circumference of the wheel?

• 177.49 inches
• 167.41 inches
• 157.41 inches
• 187.41 inches

Multiple Choice

A minute hand (radius) of a clock is 13.8 meters long. What is the circumference of the clock?

• 86.70 meters
• 76.66 meters
• 66.66 meters
• 96.66 meters

Multiple Choice

What is the circumference of a circle with a radius of 21 cm?

• 131.88 cm
• 121.99 cm
• 111.89 cm
• 141.89 cm

Multiple Choice

What is the circumference of a circle with a radius of 33 ft?

• 207.2 ft
• 197.2 ft
• 217.2 ft
• 227.2 ft

Multiple Choice

What is the circumference of a circle with a diameter of 92 in?

• 288.88 in
• 176.88 in
• 165.88 in
• 186.88 in

Multiple Choice

What is the circumference of a 12 inch (diameter) pizza?

• 37.68 inches
• 36.68 inches
• 35.68 inches
• 34.68 inches

Multiple Choice

What does "circumference" mean?

• Space a circle takes up
• Distance around a circle
• Line from one side of a circle to another
• Line from center of circle to side

Multiple Choice

Does this picture show the diameter or radius of a circle?

• Diameter
• Radius

Multiple Choice

What is the formula for circumference of a circle given the diameter?

• C = pi x r
• C = pi x 2r
• C = pi x D
• C = pi x 2D

Multiple Choice

What is the formula for circumference of a circle given the radius?

• C = pi x r
• C = pi x 2r
• C = pi x D
• C = pi x 2D

Multiple Choice

What is the diameter?

• 8
• 16
• 10
• 4

Multiple Choice

Daniel wants to buy cookies for her friend. The radius of a cookie is 5 inches. What is the cookie’s circumference?

• 10 in
• 2.5 in
• 15.7 in
• 31.4 in 

Multiple Choice

If my diameter is 19 inches, what is my radius?

• 38 inches
• 9.5 inches
• 59.66 inches
• 119.32 inches

Multiple Choice

What does C represent in the formula:

C = π·d

• Pi

• Circumference

• Diameter

• Area

Multiple Choice

What does d represent in the formula:

C = π·d

• diameter

• radius

• pi

• 3.14

Multiple Choice

What number represents π?

• 31.4

• 4.13

• 3.14

• 34.1

​Area of a Circle

​Area of a circle can be described as the middle of the pizza where we put the sauce, the cheese, the toppings.

​Area of a Circle Formula

Multiple Choice

Find the area of the circle. (use 3.14 for $$\pi$$ ) 

• 43.96

• 153.86

• 87.82

• 307.72

Multiple Choice

find the area of the circle below. (use 3.14 for $$\pi$$ ) 

• 100 cm

• 225 cm

• 9 cm

• 28.26 cm

Multiple Choice

What is the area of this circle? (use 3.14 for π)

• 163.2

• 15.3

• 124.2

• 113.04

Multiple Choice

What is the area of this circle? (use 3.14 for $$\pi$$  ).

• 15393.8  $$mi^2$$  

• 3846.5  $$mi^2$$  

• 5930.12  $$mi^2$$  

• 1248.12  $$mi^2$$  

Multiple Choice

A line from the center point to the edge of the circle

• diameter

• radio

• radius

• circumference

Multiple Choice

A line that goes from one edge of the circle to another and crosses the center point

• center

• diameter

• circumference

• radius

Multiple Choice

What is the area of a circle with a diameter of 10 cm ? (use 3.14 for $$\pi$$  ). 

• 31.4 cm²

• 78.5 cm²

• 15.7 cm²

• 314 cm²

Multiple Choice

What is the formula for area of a circle given the radius?

• A = πr
• A = 2πr
• A = πd
• A = πr²

Multiple Choice

Find the area of the circle

• 56.52
• 254.34
• 1017.36
• 113.04

Multiple Choice

what is the area of this semicircle ?
d = 8 cm 

• 100.48 cm²
• 80 cm²
• 200.96 cm²
• 25.12 cm²

Multiple Choice

What is/are the formula(s) to find the area of a circle?

• πr²
• 2πr
• √π

Multiple Choice

What does area mean?

• the distance around a shape
• half the distance around a shape
• the amount of space outside a shape
• the amount of space inside a shape

Multiple Choice

A clock face has a diameter of 10 inches. What is the approximate area of the clock face in square inches?

• 314 in²
• 31.4 in²
• 7.85 in²
• 78.5 in²

Multiple Choice

Shring's dining room table is round and has a radius of 4.5 feet. What is the tabletop's area?

• 63.585 ft²
• 68.345 ft²
• 64.585 ft²
• 61.345 ft²

Multiple Choice

Determine the radius of the penny

• 59.66 mm
• 9.5 mm
• 38 mm
• 119.32 mm

Multiple Choice

Jacob is painting a circular picture on his wall.  If the painting has a diameter of 4 ft, how much paint will he need to cover the inside of the circle?  Is this question asking you to find the area, circumference, or neither?

• area
• circumference
• neither

Multiple Choice

A cruise ship has a large, circular window. It has a diameter of 8 meters. What is the window's area?

• 31.25 m²

• 29.55 m²

• 30.36 m²

• 50.27 m²

Multiple Choice

Ms. Catall is using a compass to find her way out of the woods. The compass has a radius of 4 centimeters. What is the compass's area?

• 49.2 cm²
• 45.6 cm²
• 50.24 cm²
• 55.9 cm²