1.7/AB=DE/BE=DE/(BD+DE)=3/(BD+3)1.7/AB=GH/BH=GH/(BD+DG+GH)=5/(BD+10)∴3/(BD+3)=5/(BD+10)∴BD=7.5∴AB=1.7(BD+3)/3=1.7×(7.5+3)/3=5.95m