One of the angles of an isosceles triangle is 100 degrees. What are the others?

Suppose an angle of 100 ° is at the base. Then, by the property of an isosceles triangle, the second angle at the base is also 100 °, and their sum is 200 °. The sum of all the angles of a triangle is 180 °, which means that an angle of 100 ° cannot be at the base – an angle of 100 ° is located at the apex of an isosceles triangle. Then the sum of the two angles at the base is 180 ° – 100 ° = 80 °. Then each of the angles at the base is 80 ° / 2 = 40 °.

Answer: The angles of the triangle are 100 °, 40 ° and 40 °.