What Are Isosceles Triangles?

Isosceles triangles have two equal sides and two congruent angles

Isosceles triangles have two sides that match, and two angles that match. This means they look symmetrical.

All the triangles in the image below are isosceles.

The unique side on isosceles triangles is called the base. The point opposite the unique side is the vertex of the only unique angle, and is called the apex.

The altitude to an isosceles triangle's base bisects that base as well as the apex angle, forms the shape's only line of symmetry, and is identical to the median to that side.