Question

如圖：在平面直角坐標(biāo)系中A(2，6),B(-1，1)，C(4，3).在下圖中作出 △ABC關(guān)于y軸對(duì)稱圖形△A₁B₁C₁.

Answer 1

作圖見解析.

試題分析：要作出一個(gè)三角形關(guān)于y軸的對(duì)稱圖形,只需要作出三個(gè)頂點(diǎn)關(guān)于y軸對(duì)稱的對(duì)稱點(diǎn),然后連接這三個(gè)對(duì)稱點(diǎn)即可,如圖,過(guò)點(diǎn)A作y軸的垂線交y軸與點(diǎn)G,延長(zhǎng)AG至點(diǎn)A₁,使得AG= A₁G, 點(diǎn)A₁是點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn), 過(guò)點(diǎn)B作y軸的垂線交y軸與點(diǎn)I,延長(zhǎng)BI至點(diǎn)B₁,使得BI= B₁I, 點(diǎn)B₁是點(diǎn)B關(guān)于y軸的對(duì)稱點(diǎn), 過(guò)點(diǎn)C作y軸的垂線交y軸與點(diǎn)H,延長(zhǎng)CH至點(diǎn)C₁,使得CH= C₁H, 點(diǎn)C₁是點(diǎn)C關(guān)于y軸的對(duì)稱點(diǎn),連接A₁B₁C₁,得到圖形△A₁B₁C₁.
試題解析：

如圖,過(guò)點(diǎn)A作y軸的垂線交y軸與點(diǎn)G,延長(zhǎng)AG至點(diǎn)A₁,使得AG= A₁G, 點(diǎn)A₁是點(diǎn)A關(guān)于y軸的對(duì)稱點(diǎn), 過(guò)點(diǎn)B作y軸的垂線交y軸與點(diǎn)I,延長(zhǎng)BI至點(diǎn)B₁,使得BI= B₁I, 點(diǎn)B₁是點(diǎn)B關(guān)于y軸的對(duì)稱點(diǎn), 過(guò)點(diǎn)C作y軸的垂線交y軸與點(diǎn)H,延長(zhǎng)CH至點(diǎn)C₁,使得CH= C₁H, 點(diǎn)C₁是點(diǎn)C關(guān)于y軸的對(duì)稱點(diǎn),連接A₁B₁C₁,得到圖形△A₁B₁C₁.