Can an isosceles triangle be an equilateral triangle?

Euclid defined an isosceles triangle as one having exactly two equal sides, but modern treatments prefer to define them as having at least two equal sides, making equilateral triangles(with three equal sides) a special case of isosceles triangles. read more

In an equilateral triangle all three sides are equal. In an isosceles triangle two sides are equal. So in an equilateral triangle any two sides are equal. So the equilareral triangles are also isosceles. In an equilateral tringle all 3 angles are equal and each of them must be equal to 60 degree only. And all angles are acute. read more

An equilateral triangle is one with three equal sides. An isosceles triangle is one with two equal sides. Therefore, every equilateral triangle is isosceles, but not every isosceles triangle is equilateral. So far, so book. read more