25.如圖,在平面直角坐標(biāo)系xOy中,已知Rt△DOE,∠DOE=90°,OD=3,點(diǎn)D在y軸上,點(diǎn)E在x軸上,在△ABC中,點(diǎn)A,C在x軸上,AC=5,∠ACB+∠ODE=180°,∠B=∠OED,BC=DE.按下列要求畫圖(保留作圖痕跡):
(1)將△ODE繞O點(diǎn)按逆時(shí)針方向旋轉(zhuǎn)90°得到△OMN(其中點(diǎn)D的對(duì)應(yīng)點(diǎn)為點(diǎn)M,點(diǎn)E的對(duì)應(yīng)點(diǎn)為點(diǎn)N),在圖(1)畫出△OMN;
(2)將△ABC沿x軸向右平移得到△A′B′C′(其中A,B,C的對(duì)應(yīng)點(diǎn)分別為點(diǎn)A′,B′,C′),使得B′C′與(1)中△OMN的邊NM重合,畫出平移后的三角形A′B′C′;
(3)求OE的長.