Area and Circumference of a Circle

Other than the formula C=πd what is another formula for circumference of a circle?

• C=2π

• C=2πr

• C=πr²

• C=πd²

Trevor is making a tablecloth for a circular table with a diameter of 40 inches. How many inches of tablecloth does he need? 

• 125.6 in²

• 251.2 in²

• 1256 ft²

• 1256 in²

Ray wants to build a fence around his circular garden outside. The garden has a radius of 6 ft. How many feet of fencing does he need?

• 37.68 ft

• 18.84 ft

• 113.04 ft

• 452.16 ft

A circle pool has a radius of 7.5 ft. Monica wants to know how many ft of a pool cover she needs to buy?

• 23.55 ft²

• 176.63 ft²

• 47.1 ft²

• 706.5 ft²

The most popular size pizza at Pizza Parlor is a large pizza with a 12-inch radius. Which of the following best represents the circumference of this pizza?

• 62.84 inches

• 60 inches

• 75.36 inches

• 452.16 inches

What is the circumference of a circle with a radius of 5 in terms of π ?

• 5 π square units

• 10 π square units

• 25 π square units

• 50 π square units

What is the circumference? Round to the nearest whole number.

• 48

• 96

• 24

• 18

A Circle has a radius of 4.  What is the circumference of the circle? (Best Choice)

• 4π or about 12.56

• 16π or about 50.24

• 2π or about 6.28

• 8π or about 25.12

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

• A = πr

• A = 2πr

• A = πd

• A = πr²

A circle has an area of 36π. What is the circumference of the circle?

• 18π

• 12π

• 6π

• 36π