The measure of an inscribed angle is one-half the measure of the central angle. The measure of a circumscribed angle is 180 degrees minus the measure of the central angle.
An inscribed angle in geometry is the angle formed in the interior of a circle when two chords intersect on the circle. It can also be defined as the angle formed by two given points on a circle at a given point on the circle.
The measure of an inscribed angle is one-half the measure of the central angle. The measure of a circumscribed angle is 180 degrees minus the measure of the central angle.
m ∠ABC = m ∠ABD + m ∠DBC (∠ Addition Postulate)
m ∠ABD = 1/2 m(arc AD)
m ∠DBC = 1/2 m(arc DC)
(The measure of an inscribed ∠ whose side is diameter is half the measure of the intercepted arc (Case 1)).
m ∠ABC = 1/2 m(arc AD) + 1/2 m(arc DC) (Substitution)
m ∠ABC = 1/2 [m(arc AD) + m(arc DC)] (Factor)
m(arc AD) + m(arc DC) = m(arc AC) (Arc Addition Postulate)
m ∠ABC = 1/2 m(arc AC) (Substitution)
To learn more about inscribed angle refer to:
https://brainly.com/question/13110384
#SPJ4