I once thought that the Great Pyramid of Gaza was at 756ft x 756ft the same dimensions as Lincoln’s Inn Fields, but alas as pyramids by the laws of physics need to be absolutely square and that London square is clearly not those perfect dimensions. The Circle Line never lived up to its name, as being not exactly a circle, nowadays it doesn’t even travel in a circular direction.

So, leaving out ‘squares’, we start with the largest rectangle in London Lincoln’s Inn Fields measuring 821ft x 625ft, closely followed by Grosvenor Square or Grosvenor Oblong at 680ft x 530ft.

The smallest rectangle open to the public is Pickering Place barely large enough to have 4 tenements along one side.

The definition of a circle is that all points in the same plane must lie at an equal distance from a centre point. I’ve found very few true circles, so the largest appears to be the Inner Circle, Regent’s Park at 1,082ft diameter or at 330m diameter, curiously makes it one kilometre in circumference.

At the other end of the circle, so to speak, is Percy Circus just off King’s Cross Road, which by my calculations (I didn’t get out a tape measure) has a diameter of 246ft. It also has the unwelcome distinction of once hosting Lenin and his wife Nadia at No. 16.

For my oval, I have to point you in the direction of London’s most famous – the Kennington Oval a street surrounding the world’s famous cricket ground at 345yds x 230yds.

As for the smallest oval I’m going for Finsbury Circus, for amongst many contenders it actually is a perfect oval at 148ft x 115ft. Located near Moorgate Station on the site of the old Bethlem Royal Hospital from which the pejorative term bedlam originates.

What constitutes a triangle? Well, anyone who has sat through a tedious geometry lesson will know there are numerous examples of that shape. So rather cheekily I’m going for the Shoreditch Silicon Triangle, as the largest with Old Street (65yds along one edge), Great Eastern Street (468yds) and Shoreditch High Street (574yds), all measurements approximate.

As for the smallest triangle, its no contest from an area I know well. The Triangle, Palmers Green measuring not much larger than a substantial garden shed, but famous if only for the departure point of a number of buses.

Back to the question of squares. Manchester Square at 300ft x 280ft almost makes it, while the larger Belgrave Square 636ft x 665ft falls short by 29ft. Parliament Square seems a strong contender but has rounded corners.

So my selection of perfect squares, admittedly I’ve not tested the theory, are in no particular order: Chalcot Square; West Square; Soho Square; St. James’s Square; and Stockwell Gardens.