Finding the Radius and Diameter of a Circle

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

Determine the radius of the penny

• 59.66 mm

• 9.5 mm

• 38 mm

• 119.32 mm

If the radius of a circle is 4 inches, what is the diameter?

• 2 inches

• 2 feet

• 4 inches

• 8 inches

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

• 27pi

• 13.5

• 81

• 25pi

The definition of diameter is

• distance from the center of any point on the circle

• distance across the circle through the center

• distance from one point to another

• distance around the circle

The definition of radius is

• distance from one point to another point

• distance around the circle

• distance from the center to any point on the circle

• distance across the circle through the center

what is the formula for finding diameter

• r = 2 d

• d = 2 r

• a = m c²

• c = π 2 r

The distance from any point on the outside of a circle to the center of the circle is called what?

• Diameter

• Circumference

• Area

• Radius

The distance across a circle through the center is called what?

• Area

• Diameter

• Circumference

• Radius