由题意有AB'=AB=5若AD>AB，则AD=AB'+DB'=5+1=6由AD||BC，有DH/CH=DB'/BC，即DH/(5-DH)=1/12得DH=5/13若AD同理有DH/CH=DB'/BC，即DH/(5＋DH)=1/12得DH=5/11综合得DH=5/13或5/11
是否能陪个图
