Răspuns:
O1 + O2 + O3 + O4 = 360
invers proportionale cu numerele 20,15, 12 si 10 =>
O1 = K/20
O2 = K/15
O3 = K/12
O4 = K/10
cmmmc(20;15;12;10) = 60
³⁾k/20 + ⁴⁾k/15 + ⁵⁾k/12 + ⁶⁾k/10 = ⁶⁰⁾360
3k + 4k + 5k + 6k = 21600
18k = 21600
k = 1200
O1 = 1200/20 = 60°
O2 = 1200/15 = 80°
O3 = 1200/12 = 100°
O4 = 1200/10 = 120°