triangles all have three sides because the stem tri means 3 and its angle means sides so it has three angles which equals three sides
three
An equilateral triangle has 3 sides that are all the same. In addition, all angles are equal, too.
They could all be the same length, or two of them could be the same, or theycould all be different. In any case, when you add them all up, the number youget is called the "perimeter" of the triangle.
true