20 12 dongcheng senior high school entrance examination simulation math problem 12
1. Make a right triangle, congruent, then you can get 5DE=DC, then DE is 2?
2. if g is the vertical line of AD, then the vertical foot is k ... it is easy to draw that the triangle GKE is similar to the triangle EHD. So DE:KG=EH:GE= 1:5.