In one isosceles triangle, the apex angle is 24 degrees, and in the other isosceles triangle

In one isosceles triangle, the apex angle is 24 degrees, and in the other isosceles triangle, the base angle is 78 degrees. Are these triangles similar? Why?

Since both triangles are isosceles, their angles at the base are equal.

Determine the magnitude of the angles at the base of the first triangle.

Let its value be equal to X0, then the sum of the angles at the base is equal to 2 * X0.

Since the sum of the interior angles of the triangle is 180, then 24 + 2 * X = 180.

2 * X = 180 – 24 = 156.

X = 156/2 = 78.

The angles at the bases of the triangles are equal, then the triangles are similar in two angles – the first sign of the similarity of triangles.