Applying the understanding of the circumference of a circle to solve problems

A pizza has a diameter of 50 centimeters.  Which of the following is closest to the circumference of the pizza?  

• 157 cm
• 53.14 cm
• 150 cm
• 201.28 cm

 What are the formulas for circumference of a circle?

• C = π r

• C = π d

• C = 2 π r

• C = 2 π d

What is the circumference?

• 50.24
• 96
• 24
• 18

What is the circumference of a circle with a diameter of 9?

• 81π

• 9π

• 3π

• 6π

What is circumference and its formula?

• distance (amount) around a circle

• amount that is inside the circle

A circle has a radius of 1 in. What is the circumference?

• 3.14 in

• 6.82 in

• 6.28 in

• 2 in

What is the circumference of a circle with a radius of 2 yd?

• 18.84 yds

• 25.12 yds

• 12.56 yds

• 6.28 yds

What is the radius of a circle with a circumference of 26.69 centimeters? Use 3.14 for  $\pi$  
The radius is (a)   centimeters

Randy’s circular garden has a radius of 1.5 feet. He wants to enclose the garden edging that costs $0.75 per foot. About how much will the edging cost?

• $5.30

• $7.00

• $3.50

• $0.50

What is the formal definition of pi? 

• The ratio of a circle's circumference to  its diameter
• 3.14159
• The radius of a unit circle
• The ratio of a circles diameter to its area