Inscribed angles and central angles

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, and the sides of the angle are the chords.

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.

The area of a circle can be calculated using the formula A = πr², where r is the radius of the circle.

The inscribed angle is half the measure of the central angle that subtends the same arc.

The area is 28.26 cm² (using A = π(3)²).

The circumference of a circle is calculated using the formula C = 2πr, where r is the radius.

The diameter is twice the radius of the circle.

The radius is 8 cm (since radius = diameter/2).

The measure of an arc is the degree measure of the angle formed by two radii that connect the endpoints of the arc.

To find the measure of an inscribed angle, take half the measure of the arc that it subtends.