The step "draw the double points of the circle" is the previous worksheet (Double Points on a Circle). Steiner's Double Element Construction: 1) Double Points on a Circle: [url]http://www.geogebratube.org/material/show/id/35593[/url] [b]→2) Double Rays from a Point[/b] 3) Double Points on a Line: [url]http://www.geogebratube.org/material/show/id/35633[/url] All three use Pappus' Theorem: [url]http://www.geogebratube.org/material/show/id/35140[/url]