One of the angles is 120 degrees, and the other angle is 3 times less. Find the values of the second and third angles of the triangle.

1) The sum of the angles of the triangle is 180 °;
2) One angle is 120 °, the second angle will be:
120 ° / 3 = 40 °;
3) We get the third angle if we subtract the first and second angles from the sum of the 180 ° angles:
180 ° – 120 ° – 40 ° = 20 °.
Answer: The angles of the triangle are equal: 120 °, 40 °, 20 °.