Answer:
The Angle Addition Postulate states that the measure of an angle is equal to the sum of the measures of the smaller adjacent angles that form the larger angle. Since the adjacent angles
∠
A
D
B
∠ADB and
∠
D
B
C
∠DBC form
∠
A
D
C
∠ADC, then by the Angle Addition Postulate
m
∠
A
D
C
=
m
∠
A
D
B
+
m
∠
D
B
C
m∠ADC=m∠ADB+m∠DBC.
Step-by-step explanation:
