Parts of Circles and Central Angles

Front

What is the definition of a circle?

Back

A circle is the set of all points in a plane that are the same distance from a point called the center.

Front

What is the radius of a circle?

Back

The radius is the distance from the center of the circle to any point on its circumference.

Front

What is the diameter of a circle?

Back

The diameter is a line segment that passes through the center of the circle and has its endpoints on the circle. It is twice the length of the radius.

Front

What is the circumference of a circle?

Back

The circumference is the distance around the circle, calculated as C = 2πr, where r is the radius.

Front

What is a central angle?

Back

A central angle is an angle whose vertex is at the center of the circle and whose sides are radii that extend to the circumference.

Front

What is an arc in a circle?

Back

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

Front

What is a minor arc?

Back

A minor arc is an arc that is smaller than a semicircle.

Front

What is a major arc?

Back

A major arc is an arc that is larger than a semicircle.

Front

What is a semicircle?

Back

A semicircle is an arc that represents half 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.