1.已知,四邊形ABCD是正方形,△DEF繞點(diǎn)D旋轉(zhuǎn)(DE<AB),∠EDF=90°,DE=DF,連接AE,CF;直線AE與CF相交于點(diǎn)G、交CD于點(diǎn)P.
(1)如圖1,猜想AE與CF的關(guān)系,并證明;
(2)如圖2,BM⊥AG于點(diǎn)M,BN⊥CF于點(diǎn)N,則四邊形BMGN是
形;
(3)如圖3,連接BG,若AB=4,
,直接寫(xiě)出在△DEF旋轉(zhuǎn)的過(guò)程中,
①當(dāng)點(diǎn)E在正方形ABCD的內(nèi)部,且EF⊥CD時(shí)BG=
;
②線段BG長(zhǎng)度的最小值
.