(1)①△ABP∽△PCE ∴AB:BP = PC:CE => 4/x = (5-x)/CE => CE = 1/4*x(5-x) ②又有相似 所以 CF:BF = CE:BA => 3/8 = CE/4 => CE = 1.5 (2) tan∠PAE= 1/2 => PE = 1/2PA = > AP:PE = 2 = AB:PC = 4/PC =>PC =2 => BP =3