已知线段AB,在AB延长线上取一点C,使BC=3AB.在BA延长线上取一点D,使DA=3/2AB,E是DB中点且EB=30cm,求CD的长

题目

已知线段AB,在AB延长线上取一点C,使BC=3AB.在BA延长线上取一点D,使DA=3/2AB,E是DB中点且EB=30cm,求CD的长

答案

DB=30*2=60
DA=3/2AB
DB=DA+AB=3/2AB+AB=5/2AB=60
AB=24
CD=CB+BD=3AB+60=72+60=132