Circles

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

• C = π r
• C = 2 π r
• C = π d
• C = 2 π d

If the area of a circle is 25 π in² , then the diameter is?

• 10 in
• 5 in
• 25 in
• pi in

If the circumference of a circle is 22 π ft, what is the radius?

• 22 ft
• 11ft
• π ft
• no ft

If the circumference of a circle is 22π , what is the diameter?

• 22 ft
• 11 ft
• π ft
• 0 ft

If the circumference of a circle is 44 π feet, what is the radius?

• 22 ft
• 44 ft
• 33 feet
• 3.14 feet

If you are given the diameter, how can you calculate the radius?

• Multiply the diameter by 2
• Divide the diameter by 2
• Add 2 to the diameter
• Subtract 2 from the diameter

If the area of circle is 100 π , find the radius of the circle.

• 10 π
• 10
• 50
• 50 π

what is the formula for finding area of a circle

• C = π r²

• A = π r²

• A = π r² / 2

• C = 2 π r

What is the area of this circle?

• 163.2
• 15.3
• 124.2
• 113.1

What is the area of this circle?

• 1385.44
• 2142.12
• 5541.77
• 1289.12