Clissold's competition pool is 25 metres long and 17 metres wide. A lot of people nowadays think Pythagoras dreamt up a solution that helps us work out how far we swim if we swim corner to corner of the pool.

If we let c be the length of the hypoteneuse (the path of the diagonal swim - or the long side of the right-angled triangle) and a and b be the lengths of the other two sides (the side and end of the pool), the theorem can be expressed as the equation.