18.6.1 Regular Polygons Share the Circle's Roots
Core ideaDivide the rim into equal parts and join the points, and you get an equilateral triangle, a square, a regular hexagon — all inscribed in the very same circle.
Module goal. Move from the circumference being pi times the diameter to arc length, sector area, and regular polygons, gathering geometry into quantities you can compute, and paving the way for the next stage's use of numbers and intervals to describe shapes.