$\angle1\ and\ \angle8$  

 $\angle3\ and\ \angle7$  

 $\angle4\ and\ \angle5$  

 $\angle2\ and\ \angle5$  

 $180\degree$  

 $65\degree$  

 $115\degree$  

 $65\degree$  

 $180\degree$  

 $115\degree$  

They are congruent.

They are supplementary.

 $131\degree$  

 $180\degree$  

 $49\degree$  

 $131\degree$  

 $180\degree$  

 $49\degree$  

They are congruent.

They are supplementary.

$5x-8=3x+32$

$5x-8+3x+32=180$

$2x-10=4x+16$

$2x-10+4x+16=180$

Parallel lines have the same slope.

Parallel lines intersect at one point.

Perpendicular lines form a right angle.

vertical angles

corresponding angles

consecutive interior angles

alternate exterior angles