6、如下圖,梯形ABCD中,
【Zih Ya Chen C】評論
四邊形AEFD=(AD+EF)*高/2四邊形EBCF=(EF+BC)*高/2中線EF=(AD+BC)/2四邊形AEFD:四邊形EBCF=(AD+EF)*高/2:(EF+BC)*高/2 =(AD+EF):(EF+BC) =[AD+(AD+BC)/2]:[(AD+BC)/2+BC] =(3AD+BC):(AD+3BC)=3:8 內乘內=外乘外...