Answer:
I believe that number 7 is true.
Explanation:
8. Is not a vertical angle because 3 and 3 do not look the same. The line is clearly gone on one side.
9. Is also wrong because both angles do not make a 90 degree angle.
10. Is wrong because both angles make a 90 degree angle when it should make a be 180 degrees.
( I'm learning this subject right now so it might be wrong. Tell me if I go this right.)