You can put this solution on YOUR website! A triangle with two sides congruent is equilateral.
That happens when the third side is also congruent to the other two.
All triangles with two sides congruent are isosceles, even if we do not know or do not care how long the remaining side is.
An equilateral triangle is a special kind of isosceles triangle,
just like a square is a special kind or rectangle,
or a special kind of rhombus.
