Răspuns:
a) 90 - 25 = 75 de grade
b) 90 - 75 = 25 de grade
c) 89 de grade 60' - 40 de grade 25' = 49 de grade 35'
d) 89 de grade 59' 60'' - 54 de grade 10' 27" = 35 de grade 49' 33''
