Inscribed angles and central angles

Front

What is an inscribed angle?

Back

An inscribed angle is an angle formed by two chords in a circle which have a common endpoint. The vertex of the angle is on the circle.

Front

What is a central angle?

Back

A central angle is an angle whose vertex is at the center of the circle and whose sides are radii that extend to the circle.

Front

How do you find the measure of an inscribed angle?

Back

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

Front

What is the relationship between a central angle and its intercepted arc?

Back

The measure of a central angle is equal to the measure of its intercepted arc.

Front

If the measure of arc JH is 130 degrees, what is the measure of the inscribed angle that intercepts arc JH?

Back

The measure of the inscribed angle is 65 degrees.

Front

What is the formula for the circumference of a circle?

Back

The circumference C of a circle is given by the formula C = πd, where d is the diameter.

Front

If the diameter of a circle is 16, what is the radius?

Back

The radius r is half of the diameter, so r = 16/2 = 8.

Front

What is the relationship between the radius and diameter of a circle?

Back

The diameter is twice the length of the radius. d = 2r.

Front

If the radius of a circle is 18, what is the diameter?

Back

The diameter is 36, calculated as d = 2 * 18.

Front

What is the measure of a semicircle?

Back

The measure of a semicircle is 180 degrees.