Circles and Circumference

12 cm

If the circumference of a circle were 36 cm, about how many cm in length is its diameter?

6 cm

If the circumference of a circle were 36 cm, about how many cm in length is its radius?

diameter

Special type of chord

3

The circumference is about ____ times the length of the diameter of a circle.

6

The circumference is about ____ times the length of the radius of a circle.

diameter, radius

______ is two times the _____

definition of diameter

a chord that goes through the center of a circle

definition of circle

a set of points on a flat surface (plane) with every point equidistant from a given point called the center

definition of circumference

distance around, or the perimeter of, a circle

definition of chord

line segment connecting any two points on a circle; does not need to pass through the center of the circle

definition of radius

line segment from the center of a circle to any point on the circle