Some time ago I think I recall reading an interesting article about the triangular shape of the Market 'Square' in Lytham. To my recollection the article stated that, before the expansion and transformation of the Lytham in the 19th century, the majority of the town could be encompassed by it's three main landmarks; Lytham Hall, St Cuthbert's Church and the town centre, forming a non-equilateral triangle. Either by complete coincidence or by deliberate design the shape of Lytham's Market Square replicates this. Whether intentional or by coincidence the shape of the Market 'Square' at the centre of Lytham representing the predominant boarders of the old town is quite interesting.
Map of Lytham and a close up of it's Market Square - Click to enlarge