Circles Vocabulary

Front

What is a chord in a circle?

Back

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

Front

What is the center of a circle?

Back

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

Front

What is a secant line?

Back

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

Front

What is a radius of a circle?

Back

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

Front

What is a diameter?

Back

A diameter is a chord that passes through the center of the circle and has endpoints on the circle.

Front

What is a tangent line?

Back

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

Front

What is the point of tangency?

Back

The point of tangency is the point where a tangent line touches the circle.

Front

What is the angle formed between a radius and a tangent at the point of tangency?

Back

The angle is always a right angle, or 90 degrees.

Front

What is the relationship between a radius and a diameter?

Back

The diameter is twice the length of the radius.

Front

What is the circumference of a circle?

Back

The circumference is the distance around the circle, calculated as C = 2πr, where r is the radius.