Math Exploration (Area and Perimeter)

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

• radius

• diameter

• circumference

• area

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

• Radius

• Diameter

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

• Radius
• Diameter

What is the radius of this circle?

• 18
• 36
• 9
• 6

What is the radius of this circle?

• 12cm
• 6cm
• 24cm
• 3cm

What is the diameter of this circle?

• 3.5
• 6.5
• 6
• 7

What is the diameter?

• 5 in
• 10 in
• 3.14 in
• 15.84 in

What is circumference?

• The distance around a circle.
• The space inside the circle.
• A line from side to side passing through the center.
• A line from the center to the side.

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)

A Circle has a diameter of 18 meters. What is the circumference of the circle? (Best Choice)

• 9π or about 28.26 m

• 18π or about 56.52 m

• 81π or about 254.34m

• 324π or about 1017.36 m