In an isosceles triangle, the outer apex angle, which is opposite to the base, becomes 40 degrees

In an isosceles triangle, the outer apex angle, which is opposite to the base, becomes 40 degrees. Find the corners of the triangle.

An isosceles triangle is a triangle with equal lateral sides and equal angles at the base.

The sum of adjacent angles is 180 °. If the outside angle at the apex of the triangle is 40 °, then the angle at the apex of the triangle is:

180 ° – 40 ° = 140 ° – the top of an isosceles triangle;

The sum of all angles in a triangle is always 180 °. Let us find the sum of the same angles at the base, knowing the vertex:

180 ° – 140 ° = 40 ° – the sum of the angles at the base;

Then one angle at the base is equal to:

40/2 = 20 ° – angle at the base.

Answer: 140 °; 20 °; 20 °.