设山高BC=x,则AB= 1 2 x,由tan30°= BC BD = x 200+ 1 2 x = 3 3 ,得:3x=200 3 + 3 2 x,∴(3- 3 2 )x=200 3 ,∴(2 3 -1)x=400,解得x= 400 2 3 ?1 = 400(2 3 +1) 11 ≈162米.