Front

What is the formula for the circumference of a circle?

Back

C = 2πr, where r is the radius.

Front

What is the formula for the area of a circle?

Back

A = πr², where r is the radius.

Front

What is a chord in a circle?

Back

A line segment with both endpoints on the circle.

Front

What is a diameter?

Back

A chord that passes through the center of the circle, equal to twice the radius.

Front

What is a tangent to a circle?

Back

A line that touches the circle at exactly one point.

Front

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

Back

The tangent is perpendicular to the radius drawn to the point of tangency.

Front

What is an arc in a circle?

Back

A portion of the circumference of a circle.

Front

What is the measure of a semicircle?

Back

180 degrees.

Front

If the measure of arc ABC = 210°, what is the measure of the remaining arc AC?

Back

150°.

Front

What is the relationship between the central angle and the arc it subtends?

Back

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