The distribution of voting composition in the 1987 British general election (Colour).

650 constituencies are shown as circles, coloured by the quartile distribution of their votes, projected upon the electoral triangle (Appendix C) software by author on an Archimedes computer.

The pattern of voting composition forms a distinctive sickle shape in the equilateral triangle. The main axis runs from Labour strongholds to Conservative seats which then turn towards the Liberal apex. There is a dip where the seats are marginal, and here the colour of the seats also changes as the turnout increases (from dark to light purple). The liberal wins are widely spread apart.