Circles Vocabulary Radius Diameter Area Circumference

The set of all points in a plane that are equidistant from a given point.

• Circle

• Semicircle

• Half Circle

• Point

The distance from the center of a circle to a point on the circle. Endpoints are the center and a point on the circle.

• Radius

• Circumference

• Diameter

• Segment Length

Distance across a circle, through the center of the circle.

• Diameter

• Radius

• Chord

• Segment

The distance around the circle (perimeter)

• Circumference

• Area

• Circle

• Length

What is the circle's radius?

• 3 m

• 6 m

• 12 m

What is the area of a circle with a diameter of 8 inches?

What is the radius?

• 33 cm

• 66 cm

• 132 cm

If the diameter of a circle is 14 cm, what is its area?

• 5 cm

• 10 cm

• 15 cm

• 20 cm

If my circumference is 37.68cm, what is my diameter?

• 12 cm

• 118.3152 cm

• 6 cm

• 37.68 cm