Circles Review

A DVD has a diameter of 15 millimeters. Which equation would help you determine the circumference? (a)  

• c = 15π
• c = 2π15
• c = π(15²)
• c = π(7.5²)

What is the diameter of this circle?

Mathematical Equivalence

ON

What is the radius of this circle?

Mathematical Equivalence

ON

Is the red line a radius or diameter of the circle? (a)  

• Radius
• Diameter

Is the red line a radius or diameter of the circle?

• Radius
• Diameter

Determine the radius of the penny

• 59.66 mm
• 9.5 mm
• 38 mm
• 119.32 mm

Tags

CCSS.7.G.B.4

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

Tags

CCSS.7.G.B.4

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

Tags

CCSS.7.G.B.4

what is the formula for finding area of a circle

• C = π r²

• A = π r²

• A = π r² / 2

• C = 2 π r

A Circle has a diameter of 10 centimeters.  What is the circumference of the circle? (Best Choice)

• 5π or about 15.7 cm
• 10π or about 31.4 cm
• 20π or about 62.8 cm
• 100π or about 314 cm