Naming Parts of Circles

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 straight line that passes through the center of the circle and touches two points on its circumference. It is twice the length of the radius.

Front

What is the circumference of a circle?

Back

The circumference is the total distance around the circle.

Front

What is a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circle.

Front

What is an arc in a circle?

Back

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

Front

What is a sector in a circle?

Back

A sector is a region enclosed by two radii and the arc between them.

Front

What is a major arc?

Back

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

Front

What is a minor arc?

Back

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

Front

How do you name a major arc?

Back

A major arc is named using three points, with the middle point being on the arc.

Front

How do you name a minor arc?

Back

A minor arc is named using two points, which are the endpoints of the arc.