Circle Vocab

Front

What is a Radius?

Back

A radius is a line segment from the center of a circle to any point on its circumference.

Front

What is a Diameter?

Back

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

Front

What is a Chord?

Back

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

Front

What is a Tangent Line?

Back

A tangent line is a straight line that touches the circle at exactly one point.

Front

What is a Secant?

Back

A secant is a line that intersects a circle at two points.

Front

What is a Sector?

Back

A sector is a region of a circle bounded by two radii and the arc between them.

Front

What is an Arc?

Back

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

Front

What is the Center of a Circle?

Back

The center of a circle is the point that is equidistant from all points on the circle.

Front

How do you calculate the Diameter from the Radius?

Back

Diameter = 2 x Radius.

Front

How do you calculate the Radius from the Diameter?

Back

Radius = Diameter / 2.