28.已知在矩形ABCD中,AD=9,AB=12,O為矩形的中心;在Rt△AEF中,∠EAF=90°,AE=6,AF=8.將△AEF繞點(diǎn)A按順時(shí)針方向旋轉(zhuǎn)一周.
(1)當(dāng)直角邊AE,AF分別在AD,AB邊上時(shí),連接OE,OF,求△OEF的面積;
(2)設(shè)斜邊EF與矩形ABCD的交點(diǎn)為G,當(dāng)O,E,F(xiàn)三點(diǎn)在一條直線時(shí),求
的值;
(3)連接CE,取CE中點(diǎn)M,連接FM,求FM的取值范圍.