Circles and Circumference, Area

What is the diameter?

• 8
• 16
• 10
• 4

Which method could be used to find the radius of the circle formed by the pinwheel as it spins?

• Divide 9 inches by 2
• Divide 9 inches by pi
• multiply 9 inches by pi
• multiply 9 inches by 2

What is the circumference?

• 48
• 96
• 24
• 18

What is the radius?

• 18
• 72
• 38
• 14

What is the circumference?

• 36
• 18pi
• 108pi
• 36pi

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

A bicycle tire has a diameter of 27 inches. What is the radius?

• 27pi
• 13.5
• 81
• 25pi

A bicycle tire has a diameter of 27 inches. How far does the bike travel along the ground when the wheel rotates once? What is the circumference of this tire?

• 81
• 15.5
• 27
• 13

The distance around a circle; much like the perimeter of a rectangle.

• perimeter
• diameter
• circumference
• radius

What is the area of a circle?

• The distance around a circle.

• The space inside the circle.

• The length of the straight line segment that passes through the center of the circle and whose endpoints lie on the circle.

• The line from the center of a circle to any point on its edge.