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AB
Try it on the Geometry BoardUses:Midpoint and perpendicular bisectorPerpendicular at a point

Regular polygon on a segment: 10 sides

Builds a regular polygon on a segment, with its corners and sides. Ruler and compass only.

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Part 1 of 9: Make the golden length (1 of 3)Step 1 of 12Compass

First a right angle at the end of the side. Put the point of your compass on B.

Keys: left and right arrows step, Space plays or pauses, Escape goes back to all constructions.