11. ∠MON = 160°, ∠MOK – ∠NOK = 40°, ∠MOK, ∠NOK - ?

Пусть ∠NOK = x, тогда ∠MOK = x + 40°.

∠MON = ∠MOK + ∠NOK

160° = x + 40° + x

2x = 160° - 40°

2x = 120°

x = 60°

∠NOK = 60°

∠MOK = 60° + 40° = 100°

∠NOK = 60°, ∠MOK = 100°