1) x+y =90 grade
78 gr 15' 30'' +y =90
y =90 gr-78 gr 15' 30'' =
90 gr = 89 gr 59' 60 '' -
78 gr 15' 30 ''
------------------------------
11 gr 44' 30''
2)x+y =180 gr
78 gr 15' 30''+ y =180
y =180 -78gr 15'30''=
180 gr = 179 gr 59'60''-
78 gr 15'30''
--------------------------------
101 gr 44'30''