Whilst the above is technically correct, in terms of the 'spirit' (if nothing else) in which the route is planned and executed, any triangular route which involves one overly short leg (eg 5 miles would seem relatively short to me) and therefore two very similar lengths is generally to be discouraged as one then becomes a near retrace of the other. As a FI, I always got my students (both PPL and CPL) to plan for a near perfect triangular route which has the added advantage of balancing out flight time between airfields.