Question

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 1

CDE = 10

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! :)