# The angles at the base of an isosceles triangle add up to 90. Find the outer corners of this triangle.

September 20, 2021 | education

| The condition says that the sum of the angles at the base of an isosceles triangle is 90 °. In order to find the outer corners of this triangle, let’s first find the inner corners of the triangle.

So, the sum of the angles of a triangle is 180 °. We are looking for the degree measure of the third angle:

180 ° – 90 ° = 90 ° apex angle.

90 °: 2 = 45 ° angles at the base.

The sum of adjacent angles is 180 °.

180 ° – 90 ° = 90 ° outside angle at the apex of the triangle;

180 ° – 45 ° = 135 ° outside angles at each of their angles at the base of the triangle.

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.