Parts of a Circle

Front

What is a circle?

Back

A circle is a set of points in a plane that are equidistant from a fixed 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 a chord in a circle?

Back

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

Front

What is a secant line?

Back

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

Front

What is a tangent line?

Back

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

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 of the circle.

Front

What is an arc in a circle?

Back

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

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.