



 
Lias continued.
Hi Lisa. 1. Corresponding angles formed by a transverse line crossing two parallel lines are congruent, therefore angle CAB equals angle ACD and that's x in your diagram. 2. For similar reasons, angle ABC equals angle DCE and that's also x. The final step is connected to another problem you sent us.
Can you formalize this and complete the proof? The PS: Your web camera really helped!
 


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