Circle Vocabulary

Front

What is the longest part of a circle?

Back

Diameter

Front

Define a true circle.

Back

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

Front

What is the segment from the center to the edge of a circle called?

Back

Radius

Front

What do you call a line segment that touches a circle at exactly one point?

Back

Tangent

Front

What is a segment that has one endpoint at the center and the other endpoint on the circle?

Back

Radius

Front

What is the distance around a circle called?

Back

Circumference

Front

What is a line segment whose endpoints lie on the circle?

Back

Chord

Front

What is the longest chord in a circle?

Back

Diameter

Front

What is the area of a circle formula?

Back

A = πr², where r is the radius.

Front

What is the relationship between the diameter and the radius?

Back

The diameter is twice the length of the radius.