Circle Unit Vocabulary

Front

What is the relationship between an inscribed angle and the arc it intercepts?

Back

The arc is two times the measure of the inscribed angle.

Front

What do you call an arc of a circle that measures exactly 180 degrees?

Back

Semicircle.

Front

What is the distance between two points on a circle called?

Back

Diameter.

Front

What is the distance from the center of a circle to a point on the circle called?

Back

Radius.

Front

What is defined as the set of all points that are a fixed distance from a central point?

Back

Circle.

Front

What is the formula for the circumference of a circle?

Back

C = 2πr, where r is the radius.

Front

What is the area of a circle?

Back

A = πr², where r is the radius.

Front

What is a central angle?

Back

An angle whose vertex is at the center of the circle and whose sides intersect the circle.

Front

What is the relationship between a central angle and the arc it intercepts?

Back

The measure of the central angle is equal to the measure of the intercepted arc.

Front

What is a chord in a circle?

Back

A line segment whose endpoints lie on the circle.