25.平面直角坐標(biāo)系中,點(diǎn)A,C分別是x軸和y軸上的動(dòng)點(diǎn),∠ACB=90°,AC=BC.
(1)如圖1,若A(-6,0),C(0,3),求點(diǎn)B的坐標(biāo);
(2)如圖2,設(shè)BC交x軸于點(diǎn)D,若AD平分∠BAC,AD=8,求點(diǎn)B的縱坐標(biāo);
(3)如圖3,當(dāng)點(diǎn)C運(yùn)動(dòng)到原點(diǎn)O時(shí),∠BAO的平分線交y軸于點(diǎn)E,F(xiàn)(t,0)為線段OA上一點(diǎn),將△EOF沿EF翻折,F(xiàn)O的對(duì)應(yīng)邊的延長(zhǎng)線交AB于點(diǎn)G,H為線段AG上一點(diǎn),且EF=EH,求FG+HG的值.(用含t的式子表示)