2102: full circle

Each of the four paired lights (at 1A/4, 13/14, 30/31 and 32/33) forms a RIGHT ANGLE which is the solution in each case. Four right angles equal THREE SIXTY DEGREES (the solutions at 23/40/15), thus making the FULL CIRCLE of the title.

First prize R.R. Alford, Oundle, Peterborough

Runners-up Jenny Atkinson, Little Chalfont, Bucks; Lewis Corner, South Fremantle, Western Australia