Math quiz- Circumference and Area

Circumference and Area

Multiple Choice

If the diameter is 48m, what is the radius?

• 96m

• 24m

• 12m

• 4m

Circumference is...

C = d π or diameter times pi

C = 2 π r or radius times 2 times pi

π is 3.14

Multiple Choice

A circle has a RADIUS of 15 cm. What is the CIRCUMFERENCE of this circle?

• 47.1 cm because you multiply 15 and π

• 94.2 cm because you multiply 30 and π

Multiple Choice

A circle has a DIAMETER of 20m. What is the circumference of this circle?

• 31.4m

• 62.8m

Area

remember to use the radius in finding area. If you are given a DIAMETER, divide it by 2.

To square the radius we multiply it to itself.

Example: 9² = 9x9 = 81

Multiple Choice

What measurement of a circle do you need to find the AREA?

• Diameter

• Radius

Area

remember to use the radius in finding area. If you are given a DIAMETER, divide it by 2.

To square the radius we multiply it to itself.

Example: 9² = 9x9 = 81

Multiple Choice

What is the area of the circle shown?

• 113.04

• 452.16

Multiple Choice

What is the AREA of a circle with a radius of 7cm?

• 21.98cm

• 153.86cm

• 43.96cm

Multiple Choice

The distance halfway across the circle is called the...

• radius

• diameter

• circumference

• area

Multiple Choice

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

• Radius

• Diameter

Multiple Choice

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

• Radius
• Diameter

Multiple Choice

What is the radius of this circle?

• 12cm
• 6cm
• 24cm
• 3cm

Multiple Choice

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

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