The bisector AL is drawn in triangle ABC, the angle ALC is 37 °, the angle ABC is 25 °. Find the angle of the ACB.

Consider the triangle ABL.
∠BLA = 180 ° -∠ALC = 180 ° -37 ° = 143 ° (as these are adjacent angles)
By the theorem on the sum of the angles of a triangle:
180 ° = ∠ABC + ∠BLA + ∠LAB = 25 ° + 143 ° + ∠LAB
∠LAB = 180 ° -25 ° -143 ° = 12 °
Consider the triangle ALC.
∠LAC = ∠LAB = 12 ° (since AL is a bisector)
By the theorem on the sum of the angles of a triangle:
180 ° = ∠ALC + ∠ACB + ∠LAC = 37 ° + ∠ACB + 12 °
∠ACB = 180 ° -37 ° -12 ° = 131 °
Answer: 131