In the accompanying diagram of the parallelogram ABCD, AB is extended to E such that CB is congruent to CE. If m< ADC = 100, what is m

Answer:
CDE = 10
Step-by-step explanation:
in parallelogram, adjacent angle are supplementary.
A+ B = 180
100 + B = 180
B = 180 - 100
B = 18
E ≅ B
E = 80
EC⊥ DC
DCE = 90
in ΔDCE,
DCE + CED + CDE= 180 {Angle sum property of triangle}
90 + 80 + CDE = 180
170 + CDE = 180
CDE = 180 - 170
CDE = 10
Hope this helps! :)