Area & Circumference of Circles

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

• Radius
• Diameter

What is the area of this circle? Use the Pi button. (a)  

• 452.39 cm²
• 139.12 cm²
• 113.1 cm²
• 84.23 cm²

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.

What is the area of a circle?

• 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.

The homeowners association wants to enclose the playground in a fence. How much fencing will they need to purchase? (a)  

• area
• circumference
• neither

What is the radius of this circle?

• 18 in

• 36 in

• 9 in

• 8 in

Steven purchases a bowl. The diameter of the

bowl is 14 cm. What is the distance around the bowl? Use the Pi button.

• 21.98 cm

• 43.98 cm

• 87.96 cm

• 7 cm

What is the formula for area of a circle?

• A = 2πr

The radius is....

• a line that crosses through the center and touches each edge 
• the center point of a circle 
• a line from the center point to the edge of the circle
• an element in science

Find the area of the circle below.

• 100 cm²

• 225 cm²

• 9 cm²

• 28.27 cm²