Arc Measure and Arc Length

Front

What is an arc in a circle?

Back

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

Front

Define minor arc.

Back

A minor arc is an arc that measures less than 180 degrees.

Front

Define major arc.

Back

A major arc is an arc that measures more than 180 degrees.

Front

What is a semicircle?

Back

A semicircle is an arc that measures exactly 180 degrees.

Front

How do you find the measure of a minor arc?

Back

The measure of a minor arc is equal to the measure of the central angle that subtends it.

Front

How do you find the measure of a major arc?

Back

The measure of a major arc is 360 degrees minus the measure of the minor arc.

Front

What is the formula for arc length?

Back

Arc length = (θ/360) * 2πr, where θ is the central angle in degrees and r is the radius.

Front

If the radius of a circle is 10 cm and the central angle is 60 degrees, what is the arc length?

Back

Arc length = (60/360) * 2π(10) = (1/6) * 20π = (10/3)π cm.

Front

What is the relationship between the measures of a minor arc and its corresponding major arc?

Back

The sum of the measures of a minor arc and its corresponding major arc is always 360 degrees.

Front

How do you identify a minor arc, major arc, or semicircle?

Back

A minor arc is less than 180 degrees, a major arc is more than 180 degrees, and a semicircle is exactly 180 degrees.