$76.80 minus 12 1/2 is $64.30.
Complement adds to 90
complement of A is 90-A
supplement is adds to 180
supplemetn of A is 180-A
2(90-A) is -40+180-A
2(90-A)=-40+180-A
2(90-A)=140-A
distribute
180-2A=140-A
add 2A to both sides
180=140+A
minus 140 both sides
40=A
A=40 degres
The others don’t make any sense so it has to be “A”.