2025 Circles Retake Review

Front

What is a circle?

Back

A circle is a shape consisting of all points in a plane that are at a given distance from a fixed point, called the center.

Front

What is the diameter of a circle?

Back

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

Front

What is a chord in a circle?

Back

A chord is a line segment with both endpoints on the circle.

Front

What is the relationship between a diameter and a chord?

Back

A diameter is a special type of chord that passes through the center of the circle.

Front

What does it mean for a diameter to be perpendicular to a chord?

Back

It means that the diameter intersects the chord at a right angle (90 degrees).

Front

How do you find the measure of an angle formed by two intersecting chords?

Back

The measure of the angle is equal to half the sum of the measures of the arcs intercepted by the angle.

Front

What is the measure of an arc?

Back

The measure of an arc is the degree measure of the angle that subtends the arc at the center of the circle.

Front

What is the relationship between the angles formed by a tangent and a chord?

Back

The angle formed by a tangent and a chord through the point of contact is equal to the measure of the opposite arc.

Front

How do you solve for unknown variables in circle geometry?

Back

Use properties of circles, such as the relationships between angles, arcs, and chords, to set up equations and solve for the unknowns.

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) is calculated using the formula C = πd, where d is the diameter.