■DE群多面体の面数公式(その801)
[1]E5=121
頂点間距離が2のとき,半径は√(5/2)
R^2=1+1/3+1/6+1/10+a5^2=5/2
=1+1/3+1/6+2/4+b5^2
1+1/3+1/6=(6+2+1)/6=3/2
R^2=3/2+1/2+b5^2=3/2+1/10+a5^2=5/2
a5^2=(25−15−1)/10=9/10
b5^2=(25−15−5)/10=1/2
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[2]E4=t1α4
頂点間距離が2のとき,半径は√(12/5)
R^2=1+1/3+1/6+a4^2=12/5
=1+1/3+2/3+b4^2
1+1/3=(3+1)/3=4/3
R^2=4/3+2/3+b4^2=4/3+1/6+a4^2=12/5
a4^2=(72−40−5)/30=9/10
b4^2=(72−40−20)/30=4/10
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[3]E3=正三角柱
頂点間距離が2のとき,半径は√(7/3)
R^2=1+1/3+a3^2=7/3
=1+2/2+b3^2
R^2=2+b3^2=4/3+a3^2=7/3
a3^2=1
b4^2=1/3
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