P88-11 h,n=d-n=1586-0435=1151mm Ba h=H4-Ha=-1.151m B点比A点高P88-11 ◼ B点比A点高。 h h H H m h d n m m B A A B A B A B 1.151 1586 0435 1151 = − = − = − = − = − =