Most importantly, though, green lines through the corners of the decagon intersect the upper yellow horizontal precisely at the left and right margins of the panel, suggesting that its aspect ratio was determined by this construction. Further evidence for the relevance of the green lines comes from the way the descending one aligns with the faces of Venus and her child, Mars’s left leg, and the bottom edge of his discarded armor, while the right one aligns with Venus’s finger, her genital, and Mars’s right knee, arm, and shoulder.
This panel of Mars and Venus has a fairly subtle proportional scheme based, rather surprisingly, on the idea of decagonal symmetry ; several steps will be necessary to see this. The first clue in this direction may be seen near the bottom right corner, where the sharp reflection in the shoulder joint of Mars’s discarded armor has the characteristic 72-degree slope characteristic of decagons. Not only the angle but also the location of this reflection line proves significant.
