Home > Draw > Regular Polygon: Center, Vertex

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A regular polygon around a center, sized out to a corner.

Menu: Draw > Regular Polygon: Center, Vertex | In depth: Rectangles & squares

The tool asks how many sides first, then takes the center and one corner. The distance between them is the circumradius - the reach from the middle to a point of the shape.

CAD calls this inscribed, meaning the polygon sits inside a circle through its corners. The button says what you click instead, because the two CAD words describe the polygon's relation to a circle you cannot see, and the one called circumscribed is the one with the smaller radius - which is the wrong way round from how most people read it.

Regular Polygon: Center, Edge Midpoint takes the same two clicks and reads the second one as the middle of a side instead. A corner is further from the center than a side's middle, so the same two points give a smaller polygon here than they do there.

The center and the corner you clicked stay yours. Every other corner is derived from them, so dragging either one keeps the shape regular instead of shearing it.

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. Seven, nine, eleven, thirteen, fourteen and eighteen are not among them. This tool places corners by angle, so it will draw any count from 3 up.

< Previous: Regular Polygon: Edge | Next: Regular Polygon: Center, Edge Midpoint >

• Regular Polygon: Center, Edge Midpoint - the same two clicks, read as a flat.
• Regular Polygon: Edge - build from the first side instead.