3. ∠S = x; ∠P = ∠R = 1,5х
1,5х + 1,5х + х = 180
4х = 180
х = 45 (∠S)
(180 - 45) : 2 = 67, 5 (∠P, ∠R)
4. 0,4∠L = (180 - 140) = 40 (это ∠Q)
∠L = 40 : 0,4 = 100
∠М = 180 - 100 - 40 = 40
