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AB
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Equilateral triangle on a segment

Builds an equilateral triangle on a segment, with its corners and sides. Ruler and compass only.

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Part 1 of 2: Arcs from A and BStep 1 of 6Compass

Each side is as long as the first. Put the point of your compass on A.

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