Occasionally, mathematical olympiads contain no classical Euclidean geometry. One such example is the IMO paper in the action thriller X+Y, which encompasses discrete combinatorics, additive combinatorics and algebra. To compensate for this, I have designed a cipher based entirely on Euclidean plane geometry.
The 40th cipher; click to enlarge.
As usual, there is a solvers’ area protected by a password contained within the cipher.