§19.1 命题与定理
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§19.1 命题与定理. 试判断下列句子是否正确. ( 1 )如果两个角是对顶角,那么这两个角相等; ( ) ( 2 )两直线平行,同位角相等; ( ) ( 3 )同旁内角相等,两直线平行; ( ) ( 4 )平行四边形的对角线相等; ( ) ( 5 )直角都相等 . ( ) - PowerPoint PPT Presentation
Transcript of §19.1 命题与定理
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