Unit 3.2.1 Arc Length

Front

What is the formula for arc length?

Back

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

Front

In circle O, if the radius is 4 and the measure of minor arc AB is 120 degrees, what is the length of minor arc AB?

Back

8 (calculated using the formula for arc length).

Front

What is a central angle?

Back

A central angle is an angle whose vertex is at the center of a circle.

Front

If Tasha's circular area has a radius of 24 feet and the angle between her dog house and hydrant is 165 degrees, what is the length of the arc from the dog house to the hydrant?

Back

69 feet (calculated using the arc length formula).

Front

What is the relationship between the radius and the arc length in a circle?

Back

The arc length is directly proportional to the radius and the angle subtended by the arc.

Front

How do you convert degrees to radians?

Back

Multiply degrees by (π/180).

Front

What is the circumference of a circle?

Back

Circumference = 2πr, where r is the radius.

Front

If the radius of a circle is doubled, how does the arc length change for the same angle?

Back

The arc length also doubles.

Front

What is the measure of a full circle in degrees?

Back

360 degrees.

Front

How do you find the length of a minor arc?

Back

Use the formula: Arc Length = (θ/360) × 2πr.