Answer:
Angle1 and Angle2 are supplementary.
Explanation:
There are at least 8 pairs and I want to say up to maybe 16 pairs if angles that are supplementary.
Supplementary angles add up to 180°. So any pair that is lying together on a straight line (that's 180°) are supplementary:
1&2
2&4
3&4
1&3
5&6
6&8
7&8
5&7
Since angles don't have to touch in order to be supplementary there are many more pairs.