已知,△ABC是等邊三角形,AB=8,點(diǎn)D在BC上,BD=6,點(diǎn)E是邊AB上一動(dòng)點(diǎn),將DE繞點(diǎn)D順時(shí)針旋轉(zhuǎn)60°得到線段DF.
(1)如圖1,當(dāng)點(diǎn)F恰好落在AC邊上時(shí),求線段BE的長(zhǎng);
(2)如圖2,點(diǎn)F到DE的距離FG=932,請(qǐng)直接寫出線段BE的長(zhǎng);
(3)在點(diǎn)E運(yùn)動(dòng)中,連接AF,當(dāng)線段AF的長(zhǎng)最小時(shí),請(qǐng)直接寫出△ABF的周長(zhǎng).

FG
=
93
2
【考點(diǎn)】幾何變換綜合題.
【答案】(1)線段BE的長(zhǎng)為2;
(2)線段BE的長(zhǎng)為5;
(3)當(dāng)線段AF的長(zhǎng)最小時(shí),△ABF的周長(zhǎng)為8++.
(2)線段BE的長(zhǎng)為5;
(3)當(dāng)線段AF的長(zhǎng)最小時(shí),△ABF的周長(zhǎng)為8+
3
43
【解答】
【點(diǎn)評(píng)】
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發(fā)布:2024/7/14 8:0:9組卷:372引用:1難度:0.1
相似題
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1.定義:將圖形M繞點(diǎn)P順時(shí)針旋轉(zhuǎn)90°得到圖形N,則圖形N稱為圖形M關(guān)于點(diǎn)P的“垂直圖形”.
例如:在圖中,點(diǎn)D為點(diǎn)C關(guān)于點(diǎn)P的“垂直圖形”.
(1)點(diǎn)A關(guān)于原點(diǎn)O的“垂直圖形”為點(diǎn)B.
①若點(diǎn)A的坐標(biāo)為(0,2),直接寫出點(diǎn)B的坐標(biāo);
②若點(diǎn)B的坐標(biāo)為(2,1),直接寫出點(diǎn)A的坐標(biāo);
(2)已知E(-3,3),F(xiàn)(-2,3),G(a,0).線段EF關(guān)于點(diǎn)G的“垂直圖形”記為E'F',點(diǎn)E的對(duì)應(yīng)點(diǎn)為E',點(diǎn)F的對(duì)應(yīng)點(diǎn)為F'.
①求點(diǎn)E'的坐標(biāo);
②當(dāng)點(diǎn)G運(yùn)動(dòng)時(shí),求FF'的最小值.發(fā)布:2025/5/23 23:30:1組卷:411引用:3難度:0.3 -
2.如圖1,在△ABC中,∠BAC=90°,AB=AC=4,點(diǎn)E為邊AC上一點(diǎn),以AE為斜邊,在△ABC外,作△ADE,使得∠ADE=90°,且DE=DA.現(xiàn)將△ADE繞點(diǎn)A逆時(shí)針旋轉(zhuǎn),旋轉(zhuǎn)角為α(0°<α<90°),連接BE.
(1)如圖2,當(dāng)α=15°且BE∥AD時(shí),求BE的長(zhǎng);
(2)連接CE,設(shè)CE的中點(diǎn)為點(diǎn)F,AE的中點(diǎn)為點(diǎn)H,連接DF,直線DF與線段BE交于點(diǎn)G,連接GH.
①求證:DF⊥BE;
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(1)若AE∥BD如圖(1),求旋轉(zhuǎn)角∠BAD度數(shù);
(2)當(dāng)旋轉(zhuǎn)角為60°時(shí),延長(zhǎng)ED與BC交于點(diǎn)F,如圖(2).求證:AC平分∠DAF;
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