Answer:
y = -9.3 
if they are complementary it is 45 degrees 
if they are supplementary it is 90 degrees 
Explanation:
-12.7 = y -3.4 
-12.7 + 3.4 = y -3.4 + 3.4 
-9.3 = y
complementary angles equal to 90 degrees
supplementary angles equal to 180 degrees 
vertical angles have same degrees 
so 90/2= 45 
180/2 =90