Parts of a Circle Vocab

Front

What is the diameter of a circle?

Back

The diameter is the longest distance across a circle, passing through the center. It is twice the length of the radius.

Front

What is a tangent line?

Back

A tangent line is a straight line that touches the circle at exactly one point, without crossing it.

Front

What is a chord in a circle?

Back

A chord is a line segment whose endpoints lie on the circle. It does not have to pass through 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 circumference of a circle?

Back

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

Front

What is a secant line?

Back

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

Front

What is the relationship between diameter and radius?

Back

The diameter is twice the length of the radius (D = 2r).

Front

What is the area of a circle?

Back

The area of a circle is calculated using the formula A = πr², where r is the radius.

Front

What is the center of a circle?

Back

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

Front

What is an arc in a circle?

Back

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