The angle against the base of an isosceles triangle is four times the angle at the base. Find the corners of the triangle.

The angle at the base is taken as (x) degrees, then the angle opposite to the base will be (4x) degrees. In an isosceles triangle, the angles at the base are equal, which means the third angle will also be (x) degrees.

In any triangle, the sum of the angles is 180 degrees.

x + x + 4x = 180;

5x = 180;

x = 180: 5;

x = 36 (deg.) – the degree measure of the angles at the base.

4x = 36 * 4 = 144 (deg.) – the degree measure of the angle opposite to the base.

Answer. 36 degrees, 36 degrees, 144 degrees.