Question

如圖，將三角形ABC繞點(diǎn)O旋轉(zhuǎn)得到三角形A/B/C/，且∠AOB=300，∠AOB/=200，則

（1）點(diǎn)B的對(duì)應(yīng)點(diǎn)是________________;

（2）線段OB的對(duì)應(yīng)線段是____________;

（3）∠AOB的對(duì)應(yīng)角是________________;

（4）三角形ABC旋轉(zhuǎn)的角度是__________;

 

 

Answer 1

B′，OB′，∠A′OB′，50°．

【解析】

試題分析：△ABC經(jīng)過(guò)旋轉(zhuǎn)得到△A′B′C′，旋轉(zhuǎn)中心為點(diǎn)O，點(diǎn)B的對(duì)應(yīng)點(diǎn)是B′，線段OB的對(duì)應(yīng)線段為OB′，∠AOB對(duì)應(yīng)∠A′OB′，旋轉(zhuǎn)角∠BOB′=∠AOB+∠AOB′．

試題解析：依題意，△ABC經(jīng)過(guò)旋轉(zhuǎn)得到△A′B′C′，

可知：旋轉(zhuǎn)中心為點(diǎn)O，點(diǎn)B的對(duì)應(yīng)點(diǎn)是B′，線段OB的對(duì)應(yīng)線段為OB′，

∠AOB對(duì)應(yīng)∠A′OB′，∠BOB′=∠AOB+∠AOB′=30°+20°=50°．

考點(diǎn)：旋轉(zhuǎn)的性質(zhì)．