Intro to Circles and Circumference

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

• Circle

• Semicircle

• Half Circle

• Point

The distance around the circle (perimeter)

• Circumference

• Area

• Circle

• Length

The point in the middle. The point is used to name the circle.

• Center of a Circle

• Point

• Middle Dot

• Segment

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

• Diameter

• Radius

• Chord

• Segment

What is the circumference of the following shape? (use an exact value)

• 14π mi

• 7π mi

• 49π mi

• 43.98 mi

What is the circumference of the following shape? (use an approximate value)

• 452.39 yd

• 18.85 yd

• 37.70 yd

• 113.10 yd

• A

• B

• C

• D

• E

The stained glass window is a semicircle. What is the distance around the window?

• 40.82 inches

• 66.82 inches

• 81.64 inches

• 107.64 inches

Mathematical Equivalence

ON

Find the circumference of the circle.

• 38.47 cm

• 10.99 cm

• 43.96 cm

• 21.98 cm