properties of circles

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's circumference.

Front

What is the diameter of a circle?

Back

The diameter is a straight line that passes through the center of the circle and connects two points on its circumference. It is twice the length of the radius.

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. It can be calculated using the formula C = πd or C = 2πr.

Front

What is a tangent line to a circle?

Back

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

Front

What is an arc in a circle?

Back

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

Front

What is the measure of a full circle in degrees?

Back

A full circle measures 360 degrees.

Front

What is the relationship between the measure of an arc and the angle at the center?

Back

The measure of an arc is equal to the measure of the angle formed at the center of the circle by the two radii that connect the center to the endpoints of the arc.

Front

If the measure of arc ABC is 210°, what is the measure of angle AOC?

Back

The measure of angle AOC is 150°.

Front

What is the formula for the area of a circle?

Back

The area of a circle can be calculated using the formula A = πr².