Finding the Circumference of a Circle

What is the radius of a circle?

• A line from the center to the perimeter

• Twice the diameter

• A line across the center

• The distance around the circle

How is the diameter of a circle defined?

• Twice the radius

• A line from the center to the perimeter

• Half the radius

• The distance around the circle

What is pi in mathematics?

• A formula for circles

• A type of dessert

• An irrational number

• A rational number

What is the formula for the circumference of a circle?

• C = pi / d

• C = pi * d

• C = pi + d

• C = pi - d

If the diameter of a circle is 3, what is the circumference using pi as 3.14?

• 9.42

• 15.7

• 12.56

• 6.28

How do you calculate the diameter if you know the radius is 5?

• Divide by 2

• Multiply by 3

• Add 5

• Multiply by 2

What is the circumference if the diameter is 10 and pi is used as 3.14?

• 15.7

• 62.8

• 31.4

• 20.28

What should you do if your calculated circumference is incorrect?

• Ignore the error

• Guess until it's correct

• Review and find the mistake

• Change the formula

What is the circumference of a circle with a diameter of 4 using pi as 3.14?

• 15.7

• 25.12

• 6.28

• 12.56

If the radius of a circle is 10, what is the circumference using pi as 3.14?

• 94.2

• 20.28

• 31.4

• 62.8