畫出簡單圖形旋轉(zhuǎn)90度后的圖形[例3].ppt

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1、例3畫出簡單圖形旋轉(zhuǎn)90°后的圖形圖形的運(yùn)動（三）Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.一、復(fù)習(xí)導(dǎo)入，揭示課題問題：1.還記得這個三角尺的位置是怎樣變

2、化的嗎？旋轉(zhuǎn)時點(diǎn)O的位置不變，并且每旋轉(zhuǎn)一次三角尺的兩條直角邊都繞點(diǎn)O順時針旋轉(zhuǎn)了90°。2.三角尺的旋轉(zhuǎn)有什么特點(diǎn)？Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyL

3、td.二、探究新知，明確畫法畫出三角形AOB繞點(diǎn)O順時針旋轉(zhuǎn)90°后的圖形。問題：1.自己試著畫一畫。2.你是怎么畫的？Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePty

4、Ltd.二、探究新知，明確畫法畫出三角形AOB繞點(diǎn)O順時針旋轉(zhuǎn)90°后的圖形。1.繞點(diǎn)O旋轉(zhuǎn)，點(diǎn)O的位置不變。2.先畫OA′，OA順時針旋轉(zhuǎn)90°后的位置OA′，OA′垂直于OA，點(diǎn)A′與點(diǎn)O的距離應(yīng)該是4格。3.先畫OB′，OB順時針旋轉(zhuǎn)90°后的位置OB′，OB′垂直于OB，點(diǎn)B′與點(diǎn)O的距離應(yīng)該是4格。4.連接A′B′，三角形A′OB′就是AOB繞點(diǎn)O順時針旋轉(zhuǎn)90°后的圖形。A′B′繞點(diǎn)O旋轉(zhuǎn)，點(diǎn)O的位置應(yīng)該不變。只要找出點(diǎn)A和點(diǎn)B順時針旋轉(zhuǎn)90°后的位置……Evaluationonly.Creat

5、edwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.二、探究新知，明確畫法畫出三角形AOB繞點(diǎn)O逆時針旋轉(zhuǎn)90°后的圖形。問題：1.自己試著畫一畫。2.你是怎么畫的？Evaluationonly.Crea

6、tedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.二、探究新知，明確畫法畫出三角形AOB繞點(diǎn)O逆時針旋轉(zhuǎn)90°后的圖形。1.繞點(diǎn)O旋轉(zhuǎn)，點(diǎn)O的位置不變。2.先畫OA′，OA逆時針旋轉(zhuǎn)90°后的位置OA

7、′，OA′垂直于OA，點(diǎn)A′與點(diǎn)O的距離應(yīng)該是4格。3.先畫OB′，OB逆時針旋轉(zhuǎn)90°后的位置OB′，OB′垂直于OB，點(diǎn)B′與點(diǎn)O的距離應(yīng)該是4格。4.連接A′B′，三角形A′OB′就是AOB繞點(diǎn)O逆時針旋轉(zhuǎn)90°后的圖形。A′B′Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.Evaluationonly.CreatedwithAspose.Slid

8、esfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011AsposePtyLtd.三、鞏固提升問題：你是怎樣想的？畫出三角形AOB繞點(diǎn)O逆時針旋轉(zhuǎn)90°后的圖形。Evaluationonly.CreatedwithAspose.Slidesfor.NET3.5ClientProfile5.2.0.0.Copyright2004-2011As