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hlovell
Thanks 整理如下: 第2种情形 1中心点 矩形ABCD 长a=300 宽b=200 左上角A(100,80) 中心点O‘(100+300/2, 80+200/2) 即(250,180) 左下角B(100,280) 右上角D(400,80) 右下角C(400,280) 2 顺时针旋转x(弧度) A->A' ( -150cosx-100sinx+250 , -150sinx-100cosx+180) x=0 A=A' x=π/2 A'(150,30) x=π A'=C B->B' (-150cosx+100sinx+250, -150sinx+100cosx+180) x=0,B=B' x=π/2 B'(350,30) x=π B'=D 外接矩形A1B1C1D1 A1x=B'x=(-150cosx+100sinx+250) A1y=A'y=(-150sinx-100cosx+180) B1x=B'x=(-150cosx+100sinx+250) B1y=C'y=(150sinx+100cosx+180) C1x=D'x=(150cosx+100sinx+250) C1y=A'y=(-150sinx-100cosx+180) D1x=D'x=(150cosx+100sinx+250) D1y=C'y=(150sinx+100cosx+180) 3 反时针旋转y(弧度) A->A'' (-150cosy-100siny+250, 150siny-100cosy+180) y=0 A=A'' y=π/2 A''(150,330) y=π A''=C D->D''(150cosy-100siny+250, -150siny-100cosy+180) y=0,D=D'' y=π/2 D''(150,30) y=π D''=B 外接矩形A1B1C1D1 A1x=A''x (-150cosy-100siny+250) A1y=D''y(-150siny+100cosy+180) B1x=A''x(-150cosy-100siny+250) B1y=B''y(150siny+100cosy+180) C1x=C''x(150cosy-100siny+250) C1y=B''y(150siny+100cosy+180) D1x=C''x(150cosy-100siny+250) D1y=D''y(-150cosy+100cosy+180)