Find the angles of a triangle knowing that the outer angles of its two vertices are 120 and 150 degrees.

Let’s find out what the inner angle of our figure will be when we know from the condition of the task that the outer angle is equal to 120 °:

180 – 120 = 60.

Let’s find out what the inner angle of our figure will be when we know from the condition of the task that the outer angle for it is 150 °:

180 – 150 = 30.

Let’s find out what the last inner corner of our figure will be, because we know from a school course in mathematics that the sum of the angles of such a figure is 180 °:

180 – 60 – 30 = 90.

Answer: The angles are 90 °, 30 °, 60 °.