in the diagram below, B, C and D are all on the same line, angle BAC = 24 degrees, and AB= AC = CD .

If angle ADC=X degrees, what is the value of X?

https://ibb.co/mJPMwc

sageatron2000
Apr 10, 2018

#5**+1 **

OK....!!!

Note that since AB = AC....then angles ABC and ACB are equal.....

So ACB = (180 - 24) / 2 = 156 / 2 = 78°

And ACD is supplemental to ACB...so ACD = 180 - 78 = 102°

And since AC = CD....then angles ADC and CAD are equal

So.... ADC = (180 - 102) / 2 = 78/2 = 39° = "x"

CPhill
Apr 10, 2018