Reckoning / Shape / Ring of square section
Solid · Rings
Ring of square section
A square of side w swept round an axis at distance R from its centre, like a flat washer or a gasket.
Drag to turn · pinch or scroll to zoom
Dimensions
Results
volume V
Formulas
Pappus again: area w² times the path 2πR of its centre.
Checked: the V formula agrees with a Monte Carlo measurement of the shape itself, made from its geometric definition, every time the site is built.
Topology lens
A solid with one hole through it, like a ring or a pipe. Its surface is a torus: Euler characteristic 0, genus 1. No stretching makes it a ball. More on the lens.