Saltire detected the symbol, which often appears with balls in the quadrants formed by the arms of the chi-cross, in standards that appear on the coins of Persepolis. She suggested that early Christians endorsed its solar symbolism as appropriate to Christ. She also wrote: "although it cannot be proved, ... in the white saltire of St. Andrew we still have a reminiscence of the old standard of the Persepolitan kingdom". In the old European Union standard, a black saltire set in an orange square is the hazard symbol for irritants (Xi) or harmful chemicals (Xn). It indicates a hazard less severe
Square packing in a square 7, 8, 10, 14, 15, 24, and 35. The table below shows the optimal value of "a" for , with some example packings. Other results that do not establish exact optimal packings are known. For example: Square packing in a square Square packing in a square is a packing problem where the objective is to determine how many squares of side 1 (unit squares) can be packed into a square of side "a". If "a" is an integer, the answer is "a", but the precise, or even asymptotic, amount of wasted space for non-integer "a" is an open question. The