a polygon with all sides the same length is said to be
Equilateral polygon In geometry, three or more than three straight lines (or segment of a line) make a polygon and  an equilateral polygon is a polygon which has all sides of the same length. Except in the triangle case, it need not be equiangular (need not have all angles equal), but if it does then it is a regular polygon. If the number of sides is at least five, an equilateral polygon need not be a convex polygon: it could be concave or even self-intersecting.