6.9 Warm-Up

Front

A _________ is a segment in a circle that has endpoints on the circle.

Back

Chord

Front

If the diameter of a circle is 15 in, find the circumference.

Back

15π cm

Front

Find the measure of the arc JML.

Back

176°

Front

If the C = 40π cm, find the radius.

Back

20 cm

Front

If AB = 18cm, find AR.

Back

9 cm

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr

Front

Define a radius in the context of a circle.

Back

A radius is a line segment from the center of the circle to any point on its circumference.

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the length of the radius (d = 2r).

Front

What is an arc in a circle?

Back

An arc is a portion of the circumference of a circle.

Front

How do you calculate the circumference of a circle if the radius is known?

Back

C = 2πr.