Math 10 5.5A

 $\angle2\ and\ \angle4$  

 $\angle5\ and\ \angle4$  

 $\angle1\ and\ \angle2$  

 $\angle1\ and\ \angle3$  

 $\angle1\ and\ \angle2$  are both obtuse angles.

  $m\angle1+m\angle2=180\degree.$  

 $\angle1\ and\ \angle2$  are both acute angles.

the lines are perpendicular (they form a right angle).

 $\angle1\ and\ \angle4$ 

  $\angle1\ and\ \angle2$  

 $\angle1\ and\ \angle3$  are both acute angles.

 $\angle1\ and\ \angle1.$  

the lines are parallel.

  $m\angle1+m\angle3=180\degree.$  

 $\angle1\ and\ \angle4$  are both acute angles.

 $m\angle1+m\angle4=180\degree.$  

the lines are perpendicular.

  $m\angle1+m\angle3=180\degree.$  

 $m\angle2+m\angle1=m\angle4+m\angle1$  

 $\angle2\ and\ \angle4$  must be right angles 

 $m\angle2=30\degree$  

  $m\angle2+m\angle4=m\angle6$  

 $m\angle2=m\angle4\ and\ \angle2\cong\angle4!$  

 $\angle2\ and\ \angle4$  must be right angles 

 $\angle1\cong\angle1$   

  $\angle1\cong\angle4$  

 $\angle2\cong\angle3$  

 $\angle1\cong\angle3$  

$\angle4\$ is an interior angle.

$\angle4$ is an exterior angle.

$\angle1$ is a right angle.

This triangle must be isoceles.

 $\angle2$ 

 $\angle4$ 

$\angle1$

 $\angle3$  

 $360\degree$  

 $90\degree$  

 $270\degree$  

 $180\degree$