a) 30° = 90-60⇒ c= 60°
b) 45°= 90-45 ⇒ c= 45°
c) 60° =90-30 ⇒ c=30°
d)15° 18' = 15°+18/60=15°+0,3°= 15,3°; 90- 15,3°=74,7°
e)58°3'49''= 58°+3/60+49/3600=58+0,05+0,0136(1)=58,0636(1)°
90-58,0636(1)=31,9363(8)°
f)86°59'3''
= 86+59/60+3/3600=86+0,98(3)+0,0008(3)=86,9841(6)
90-86,9841(6)=3,0158(3)°