Why don't we call an equilateral triangle an isosceles triangle?

Triangles - Equilateral, Isosceles and Scalene

Isosceles and Equilateral Triangles

Triangles

4.3 Isosceles and Equilateral Triangles

Focus The University of Tokyo

Can an equilateral triangle also be isosceles?

I am working on a woodworking project and I need to know these dimensions, I forgot how to work with Isosceles triangles, and I can't seem to find a problem similar to

Why don't we call an equilateral triangle an isosceles triangle?

Focus The University of Tokyo

All triangles are isosceles

What is a Scalene Triangle? Definition, Properties, Examples