Dodekaedro kamuts
Geometrian , dodekaedro kamutsa (edo ikosidodekaedro kamutsa ) Arkimedesen solidoetako bat da, 92 aurpegi (80 hiruki aldeberdin eta 12 pentagono erregular), 150 ertz eta 60 erpin dituena. Poliedro kirala da: bi forma ditu, bata bestearen ispilu-irudiak. Arkimedesen beste solido kiral bat baino ez dago: kubo kamutsa .
Neurriak
Dodekaedro kamutsaren neurriak
Azalera
S
=
(
20
3
+
3
25
+
10
5
)
a
2
≈
55
,
287
a
2
{\displaystyle S=\left(20{\sqrt {3}+3{\sqrt {25+10{\sqrt {5}\right)a^{2}\approx 55,287a^{2}
Bolumena
V
=
12
ξ
2
(
3
ϕ
+
1
)
−
ξ
(
36
ϕ
+
7
)
−
(
53
ϕ
+
6
)
6
3
−
ξ
2
3
a
3
≈
37
,
61665
a
3
{\displaystyle V={\frac {12\xi ^{2}(3\phi +1)-\xi (36\phi +7)-(53\phi +6)}{6{\sqrt {3-\xi ^{2}^{3}a^{3}\approx 37,61665a^{3}
Zirkunerradioa
R
=
3
−
t
4
(
2
−
t
)
a
≈
1
,
344
a
{\displaystyle R={\sqrt {\frac {3-t}{4(2-t)}a\approx 1,344a}
Inerradioa
r
=
1
4
(
2
−
t
)
a
≈
1
,
247
a
{\displaystyle r={\sqrt {\frac {1}{4(2-t)}a\approx 1,247a}
non
a
{\displaystyle a}
ertzaren luzera den,
ϕ
=
1
+
5
2
≈
1
,
6180339
{\displaystyle \phi ={\frac {1+{\sqrt {5}{2}\approx 1,6180339}
(urrezko zenbakia )
eta
ξ
=
ϕ
2
+
1
2
ϕ
−
5
27
3
+
ϕ
2
−
1
2
ϕ
−
5
27
3
≈
1
,
7155615.
{\displaystyle \xi ={\sqrt[{3}]{\frac {\phi }{2}+{\frac {1}{2}{\sqrt {\phi -{\frac {5}{27}+{\sqrt[{3}]{\frac {\phi }{2}-{\frac {1}{2}{\sqrt {\phi -{\frac {5}{27}\approx 1,7155615.}
Kanpo estekak
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