We have discussed central angles such as angle . Another kind of angle in a circle is an inscribed angle, or an angle formed by two chords that share an endpoint. In the image, angle is an inscribed angle.

It looks as though the inscribed angle is smaller than the central angle that defines the same arc. In fact, the measure of an inscribed angle is always exactly half the measure of the associated central angle. For example, if the central angle measures 50 degrees, the inscribed angle must measure 25 degrees, even if we move point  along the circumference (without going past or ). This also means that all inscribed angles that define the same arc are congruent.