Home > Draw > Regular Polygon: Edge

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A regular polygon whose first side is the two points you click.

Menu: Draw > Regular Polygon: Edge | In depth: Rectangles & squares

The tool asks how many sides first, then takes two points - or one selected segment - as the first edge. Every other corner follows from those two, so the second click finishes the shape.

It remembers the side count between runs. A pattern is usually several polygons of the same kind, and re-typing 8 for every octagon is the wrong default.

The body is built on the same side of that edge as Square and Rectangle: Directed extrude to, so a square and a hexagon drawn on the same edge land together instead of opposite ways.

The points you clicked stay yours. Every corner the tool invents is derived from them, so dragging either driver keeps the shape regular rather than shearing it - a polygon stays a polygon after the first drag, which free copies of the corners would not.

Compass and straightedge can divide a circle into n equal parts only for certain n: 3, 4, 5, 6, 8, 10, 12, 15, 16, 17, 20, 24 and so on - powers of two times a product of distinct Fermat primes (3, 5, 17, 257, 65537). Seven, nine, eleven, thirteen, fourteen and eighteen are not among them. Nine is the surprising one: three is constructible, but nine repeats that prime rather than combining distinct ones.

This tool places corners by angle, so it will draw any count from 3 up, constructible or not. Point: Divide already works the same way when it divides an arc.

< Previous: Square | Next: Regular Polygon: Center, Vertex >

• Regular Polygon: Center, Vertex - size it from the center out to a corner.
• Regular Polygon: Center, Edge Midpoint - size it from the center out to a flat.
• Square - the four-sided case, from two adjacent corners.