Circles: Arcs, Angles, Chords, Tangents

Front

What is a circle?

Back

A circle is a set of points in a plane that are equidistant from a fixed point called 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 diameter of a circle?

Back

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

Front

What is an arc in a circle?

Back

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

Front

What is a chord in a circle?

Back

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

Front

What is a tangent to a circle?

Back

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

Front

What is the measure of a central angle?

Back

The measure of a central angle is equal to the measure of the arc it intercepts.

Front

How do you find the measure of an arc?

Back

The measure of an arc can be found using the formula: Arc Measure = (Central Angle Measure) in degrees.

Front

What is the relationship between the angles formed by two tangents from a point outside the circle?

Back

The angle formed by two tangents from a point outside the circle is equal to half the difference of the measures of the intercepted arcs.

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is given by the formula: C = 2πr, where r is the radius.