16 Capítulo 16 · Neste capítulo você vai Regular polygons recognize regular polygons and prove that they are inscriptible and circumscriptible; identify center, apothem and centric angle; calculate side and apothem of the square, hexagon and equilateral triangle as a function of the radius; obtain the side of the regular decagon and pentagon and recognize the golden segment. Hexagonal nuts, honeycombs, the STOP sign, the gears of a clock: regular polygons are where you need to repeat the same piece around a center. In this chapter, we prove that every regular polygon fits exactly between two circles with the same center and we calculate its sides and apothem from the radius — calculations that, almost two thousand years ago, were used to create the first trigonometric tables.