1道几何题
矩形ABCD的长BC=4,宽AB=3,P为AD上任意1点,过P作PE垂直于AC,PF垂直于BD,垂足分别为E,F,则PE+PF的长是多少?
详细步骤啊!
参考答案:12/5
APE相似ACD得
3/5 = PE/AP
5PE = 3AP
DPF相似ACD得
3/5 = PF/(4-AP)
5PF = 12-3AP
两式相加
5(PE+PF) = 12
PE+PF = 12/5
矩形ABCD的长BC=4,宽AB=3,P为AD上任意1点,过P作PE垂直于AC,PF垂直于BD,垂足分别为E,F,则PE+PF的长是多少?
详细步骤啊!
参考答案:12/5
APE相似ACD得
3/5 = PE/AP
5PE = 3AP
DPF相似ACD得
3/5 = PF/(4-AP)
5PF = 12-3AP
两式相加
5(PE+PF) = 12
PE+PF = 12/5