Answer: supplementary angles
Assuming that the two lines are parallel:
Alternate interior angles
<5 and <7
<6 and <8
Alternate exterior angles
<3 and <9
<4 and <10
Corresponding angles
<4 and <8
<5 and <9
<3 and <7
<6 and <10
Vertical angles
<3 and <5
<6 and <4
<7 and <9
<8 and <10
Supplementary angles
<3 and <4
<4 and <5
<3 and <6
<6 and <5
<7 and <8
<8 and <9
<9 and <10
<7 and <10
<6 and <7
<5 and <8