高一几何题只解第二个.请写出解题过程,谢谢.
只解第二个.请写出解题过程,谢谢.
AA' =30 BB'=50 设,AB交平面于O 根据相似三角形性质 ====>AO:BO =3:5 ===A0 =AB*3/8 PA:PB=3:7 ====>AP =AB*3/10 ===>P0 =AO/5 做PP'垂直A'B'于P' ===>三角形PCO和AA'O相似 ===>PP' =AA'/5 =6cm