The two outer corners of the triangle are 120 and 160 degrees. find its outer third corner.

The two outer corners of the triangle are 120 and 160 degrees. find its outer third corner. Draw a conclusion about the sum of the outer angles of the triangle.

If the outer angle is 120 °, then the inner angle is 180 – 120 = 60 °. If the outer angle is 160 °, then the inner angle is 180 – 160 = 20 °. If the two inner angles of the triangle are 20 ° and 60 °, then the third inner angle is 180 – 20 – 60 = 100 °; and the external angle to it will be equal to 180 – 100 = 80 °. The sum of all the outer angles of the triangle will be 120 + 160 + 80 = 360 °. Conclusion: the sum of the outer angles of a triangle is always 360 °.