Arcs and Angles in Circles

Front

What is the definition of 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 measure of a full circle in degrees?

Back

360 degrees.

Front

What is an arc in a circle?

Back

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

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 that subtends it.

Front

What is the formula for finding the length of an arc?

Back

Arc length = (θ/360) * 2πr, where θ is the central angle in degrees and r is the radius.

Front

What is the definition of a chord in a circle?

Back

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

Front

What is the relationship between a diameter and a radius?

Back

The diameter is twice the length of the radius.

Front

What is the measure of a semicircle?

Back

180 degrees.

Front

What is the inscribed angle theorem?

Back

The inscribed angle is half the measure of the intercepted arc.

Front

How do you find the measure of an angle formed by two tangents to a circle?

Back

The angle formed by two tangents is equal to half the difference of the measures of the intercepted arcs.