Well-conditioned triangle:

The shape of the triangle in which any error in angular measurements, has a minimum effect upon the lengths of the computed sides, is known as a well conditioned triangle. Well-conditioned triangles are preferred because their apex points are very sharp and can be located by a single 'dot'. In such a case, there is no possibility of relative displacement of the plotted point.

For a well conditioned triangle, an angle must be in between 30° to 120°