I was looking at the Wikipedia page for Sphericity, and it lists that of the Disdyakis Triacontahedron at $0.9857$. This makes complete sense. However, I checked the formula for sphericity that they use, which is $$\Psi=\frac{\pi^{\frac{1}{3}}(6V)^{\frac{2}{3}}}{A}$$ and plugged it into the formulas they use for the volume, which is $$\frac{180}{11}\sqrt{179-24\sqrt{5}}$$ and the surface area, which is $$\frac{180}{11}(5+4\sqrt{5})$$ and got $0.6836$ instead. Where did my calculation go wrong?
2026-04-17 22:19:45.1776464385
What's wrong with my calculation for the sphericity of the Disdyakis Triacontahedron?
75 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in GEOMETRY
- Point in, on or out of a circle
- Find all the triangles $ABC$ for which the perpendicular line to AB halves a line segment
- How to see line bundle on $\mathbb P^1$ intuitively?
- An underdetermined system derived for rotated coordinate system
- Asymptotes of hyperbola
- Finding the range of product of two distances.
- Constrain coordinates of a point into a circle
- Position of point with respect to hyperbola
- Length of Shadow from a lamp?
- Show that the asymptotes of an hyperbola are its tangents at infinity points
Related Questions in AREA
- I cannot solve this simple looking trigonometric question
- Integrand of a double integral
- Area of Triangle, Sine
- Probability of area in a region being less than S
- Calculating an area.
- Proving formula to find area of triangle in coordinate geometry.
- Find the Side length of the shaded isosceles triangle
- Finding area bound by polar graph
- Why are there only two answers for this co-ordinate geometry question?
- Moment of inertia of a semicircle by simple integration.
Related Questions in VOLUME
- Is there a volume formula for hyperbolic tetrahedron
- An assignment for kids (Water in a container) leads to an optimization problem
- Number of unique integer coordinate points in an $n$- dimensional hyperbolic-edged tetrahedron
- Volume of a region enclosed between a surface and various planes
- Find volume of 3d solid bounded by surfaces
- Application of Gauss' Divergence Theorem
- Relative volume of $\delta$-fattening (neighborhood) of a compact set
- How to calculate volume of revolution between a curve and a line
- How to prove the space of divergence-free vector fields on a manifold is infinite dimensional?
- How do you calculate volume with cubes of fraction lengths?
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?
I get an answer of about $0.9857$ (with the same exact formula as Wikipedia) if I assume that the two constants in area and volume are swapped: if the disdyakis triacontahedron should actually have \begin{align} V &= \frac{180}{11} (5 + 4\sqrt 5) s^3 \\ A &= \frac{180}{11} \sqrt{179 - 24 \sqrt 5} s^2 \end{align} This seems like a plausible mistake to make.
I'm not entirely sure what $s$ is in these formulas, so I can't actually confirm that either of them is correct. Mathematica's
PolyhedronDatacommand gives the following values for a disdyakis triacontahedron whose shortest edge length is $1$: \begin{align} V &= \frac{1}{5} \sqrt{39612 \sqrt{5}+88590} \\ A &= \sqrt{\frac{22626}{5}+\frac{9738}{\sqrt{5}}} \end{align} Using these in the formula for sphericity gives the same result close to $0.9857$ again.