What shape has only 3 angles two of which are equal?

The shape you are referring to is a triangle with two equal angles, known as an isosceles triangle. In an isosceles triangle, two of the three angles are congruent, meaning they have the same measure. The third angle may or may not be equal to the other two angles, depending on the specific triangle. This geometric property is a fundamental concept in geometry and is often used in various mathematical applications.