Reckoning / Shape / Truncated cone (frustum)
Solid · Round solids
Truncated cone (frustum)
A cone with its top cut off parallel to the base, like a bucket or a lampshade.
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Dimensions
Results
volume V
slant height s
curved surface L
Formulas
The same algebra as the truncated pyramid, with circles for squares.
Checked: the V, L formula agrees with a Monte Carlo measurement of the shape itself, made from its geometric definition, every time the site is built.
Topology lens
Topologically a ball: its surface can be stretched onto a sphere without tearing, so its Euler characteristic is 2. More on the lens.