在△ABP中,∠ABP=180°-∠APB-∠BAP=180°-γ+β∠BPA=180°-(α-β)-∠ABP =180°-(α-β)-(180°-γ+β) =γ-α在△ABP中,由正弦定理得AP/sin∠ABP=AB/sin∠BPA即AP/sin(180°-γ+β)=a/sin(γ-α),AP=a X sin(γ-β)/sin(γ-α)∴山高h=APsinα=asinαsin(γ-β)/sin(γ-α)