Question

all equilateral triangles are isosceles,but not all isosceles triangles are equilateral.why?

Answer 1

Answer :

we know Equilateral triangle : All three sides are equal in length and all three internal angles are equal to each other .
And

Isosceles triangle : That triangle have two sides equal to each other and tow angles equal to each other .

So,

We can say all equilateral triangles are isosceles triangles . ( As special case where third side also equal )

But

All isosceles triangles are not equilateral triangle .