如图,点A1,A2,A3,…,点B1,B2,B3,…,分别在射线OM,ON上.OA1=1,A1B1=2O A1,A1 A2=2O A1,A2A3=3OA1,A3 A 4=4OA1,….A1B1∥A2B2∥A3B3∥A4B4∥….则A2B2= ,AnBn= (n为正整数).
如图,∠1的同旁内角是_____,∠2的内错角是_____.
如图,已知∠2=∠3,那么_____∥_____,若∠1=∠4,则_____∥_____.
如图,若∠1=∠2,则_____∥_____.若∠3+∠4=180°,则_____∥_____.
如图,已知直线AB、CD交于点O,OE为射线,若∠1+∠2=90°,∠1=65°,则∠3=_____.
看图填空: ∵直线AB、CD相交于点O, ∴∠1与_____是对顶角, ∠2与_____是对顶角, ∴∠1=_____,∠2=_____. 理由是: