The two corners of the triangle are 72 degrees each. Determine the value of the third angle.

It is known that 2 angles of a triangle are 72 ° each, so we find the third angle.

Since 2 angles are equal, it means that the triangle is isosceles. The sum of all the angles of the triangle is 180 °.

In order to find the third angle of an isosceles triangle, you need to subtract two known triangles from the sum of the angles of the triangle.

We get:

180 ° – 72 ° – 72 ° = 180 ° – 70 ° – 70 ° – 2 ° – 2 ° = 180 ° – 140 ° – 4 ° = 40 ° – 4 ° = 36 °.

This means that the third angle of an isosceles triangle is 36 °.