Obelisk
An obelisk is a stone pillar erected as a monument that usually consists of a pyramid atop a tall square (or sometimes rectangular base). The elongated square pyramid can therefore be considered as a special case of an obelisk.
ObeliskSolid
Obelisk
Harris and Stocker (1997) use the term "obelisk" to mean a polyhedron formed by two noncongruent parallel rectangles whose side faces are trapezoids. The volume of such a solid is given by
V = 1/6h[(2a+a^')b+(2a^'+a)b^']
(1)
= 1/6h[ab+(a+a^')(b+b^')+a^'b^'].
(2)
The distance from the bottom base to the geometric centroid is
The term obelisk is sometimes also used to refer to the dagger symbol (Bringhurst 1997, p. 275).
See also
Dagger, Elongated Square Pyramid, HemiobeliskExplore with Wolfram|Alpha
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References
Bringhurst, R. The Elements of Typographic Style, 2nd ed. Point Roberts, WA: Hartley and Marks, 1997.Harris, J. W. and Stocker, H. "Obelisk." §4.5.3 in Handbook of Mathematics and Computational Science. New York: Springer-Verlag, p. 102, 1998.Referenced on Wolfram|Alpha
ObeliskCite this as:
Weisstein, Eric W. "Obelisk." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Obelisk.html