Circumference, Arc Measure, and Arc Length

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr, where d is the diameter and r is the radius.

Tags

CCSS.7.G.B.4

Front

If the radius of a circle is 7 in, what is the circumference?

Back

C = 2π(7) = 14π in.

Tags

CCSS.7.G.B.4

Front

How many degrees are in a semicircle?

Back

180 degrees.

Tags

CCSS.4.MD.C.5B

CCSS.HSG.CO.A.1

Front

What is a minor arc?

Back

An arc that is smaller than a semicircle.

Front

What is a major arc?

Back

An arc that is larger than a semicircle.

Tags

CCSS.HSG.C.B.5

Front

What is the measure of a full circle in degrees?

Back

360 degrees.

Tags

CCSS.4.MD.C.5B

CCSS.HSG.CO.A.1

Front

If an arc measures 120 degrees, what fraction of the circle does it represent?

Back

120/360 = 1/3 of the circle.

Tags

CCSS.4.MD.C.5B

CCSS.HSG.CO.A.1

Front

What is the relationship between the central angle and the arc it intercepts?

Back

The measure of the arc is equal to the measure of the central angle.

Tags

CCSS.HSG.C.B.5

Front

If the diameter of a circle is 10 cm, what is the radius?

Back

Radius = diameter/2 = 10/2 = 5 cm.

Tags

CCSS.7.G.B.4

Front

What is the length of an arc if the radius is 4 cm and the central angle is 90 degrees?

Back

Arc length = (θ/360) * 2πr = (90/360) * 2π(4) = 2π cm.

Tags

CCSS.HSG.C.B.5