下图三角形ECD中EC=12cm，CD= 8cm，并且它的面积是长方形ABCF的2倍，那么三角形ADF的面积是请选择DCBA*V'^3X8u-q0J3T8s0N,P)W+X0S2S8N4_7\5~-~'d2m3k7?1N1x(e.Y
)W+X0S2S8N4_7\5~-~'d2m3k7?1N1x(e.Y
A．48平方厘米)W+X0S2S8N4_7\5~-~'d2m3k7?1N1x(e.Y
B．24平方厘米)W+X0S2S8N4_7\5~-~'d2m3k7?1N1x(e.Y
C．12平方厘米)W+X0S2S8N4_7\5~-~'d2m3k7?1N1x(e.Y
D．6平方厘米)W+X0S2S8N4_7\5~-~'d2m3k7?1N1x(e.Y