Angles 1, 3, 5, and 7 are obtuse angles.
Angles 2, 4, 6, and 8 are acute angles.
1) 1 and 3 are called obtuse.
3) 1 and 7 are also obtuse.
4) 4 and 6 are acute.
5) 4 and 8 are also acute.
hopes this helps a little bit :/