Honors Geometry - Arcs and Central Angles

Front

What is a central angle?

Back

A central angle is an angle whose vertex is at the center of a circle and whose sides are radii that intersect the circle.

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 measure of a central angle?

Back

The measure of a central angle is equal to the measure of the arc it intercepts.

Front

What is the difference between a minor arc and a major arc?

Back

A minor arc is less than 180 degrees, while a major arc is greater than 180 degrees.

Front

If the measure of arc AB is 120 degrees, what is the measure of the central angle AOB?

Back

The measure of the central angle AOB is also 120 degrees.

Front

What is the relationship between the length of an arc and its central angle?

Back

The length of an arc is directly proportional to its central angle.

Front

What is the formula for finding the length of an arc?

Back

Length of arc = (central angle/360) * 2πr, where r is the radius.

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 if you know the measure of the major arc?

Back

Measure of minor arc = 360 degrees - measure of major arc.

Front

What is the measure of a full circle in degrees?

Back

The measure of a full circle is 360 degrees.