Area, Perimeter, and Circumference

Area and Circumference of Circles

Multiple Choice

How are you doing today?

• Great

• Wonderful

• Awesome

• Splendid

Multiple Choice

What does a circle look like?

Multiple Choice

What would be the perimeter of a square with side lengths of 5? What would the area be?

• Perimeter 20; Area 20

• Perimeter 20; Area 25

• Perimeter 25; Area 25

• Perimeter 10; Area 20

Area and Perimeter?

Multiple Choice

What is the perimeter/area?

• Perimeter 32; Area 26

• Perimeter 26; Area 32

• Perimeter 26; Area 40

• Perimeter 40; Area 26

Important Parts of a Circle

• Radius- the distance between the center of the circle and any point on the circle itself

• Diameter- the distance between any two points on a circle which crosses through the center of the circle

• Circumference- the distance around a circle

• Area- the amount of space enclosed by the circle

Multiple Choice

Which of the following is most similar to the circumference of a circle?

• Area

• Perimeter

• Volume

• Surface Area

Multiple Choice

Which of the following is true about the diameter of a circle?

• It is always half of the radius

• It is always twice the radius

• It is always equal to the circumference

• It is always twice the circumference

Circumference and Area Formulas for a Circle

Multiple Select

Which of the following represents the formula for the circumference of a circle? (Select two)

• $$C=2\pi r$$
  

• $$C=\pi r$$

• $$C=\pi d$$

• $$C=2\pi d$$

Find the area and circumference of the circle

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Multiple Choice

Could the following dimensions exist for a circle? Radius=8 and Diameter=12

• Yes

• No

Multiple Choice

If my radius is 10ft, what is my diameter?

• 20ft
• 5ft
• 31.4ft
• 62.8ft

Multiple Choice

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

• Diameter
• Radius

Multiple Choice

Kevin is buying a cover for his circular swimming pool. If the diameter is 22 feet, how much material will it take to cover the pool? Use 3.14 for pi.

• 69.08 ft²

• 379.94 ft²

• 34.54 ft²

Multiple Choice

What is the circumference of a circle with a diameter of 19.1 ft? Use 3.14 for Pi.

• 60.00 ft

• 35.17 ft

• 28.67 ft

• 47.17 ft

Open Ended

Given that the circumference of a circle is 100, what is the radius and the diameter?

Given the area of a circle is 78.5, what is the diameter of that circle?

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Multiple Choice

Given the area of a circle is 153.86, what is the diameter of that circle?

• 7

• 14

• 28

• 3.5

Multiple Choice

Find the circumference of the circle whose area is 64 $$\pi$$  

• $$16\pi$$  
  

• $$8\pi$$  

• 16

• 8

Open Ended

Find the area of the circle whose circumference is 6 $$\pi$$  

Homework for Tonight 3/30/21

• Circles on Google Classroom

Poll

How well do you understand the material from today?

• Perfect

• Good

• Bad

• Literally not at all