Step 1. Given the side AB, draw an equilateral triangle.
Step 2. Use centre point 06. Draw the circumference in which we can inscribe the regular hexagon from side AB.
Step 3. Draw the perpendicular bisector of the segment AB. Where it intersects the circumference, we get point O12. This is the centre of the circumference in which we can inscribe a regular dodecagon from side AB.
Step 4. Divide the segment 06012 into six equal parts (Thales' theorem). Find the centres of the circumferences in which we can inscribe a heptagon O7, an octagon Os, a nonagon 0,, a decagon O1 and a hendecagon 011.
Step 5. Measure the distance between the centres of the circumferences.
Step 6. Copy it onto the perpendicular bisector. This identifies the centres of the pentagon, square and equilateral triangle (O3).
