6次元
S 6 = { x ∈ R 7 : ‖ x ‖ = r } . {\displaystyle S^{6}=\left\{x\in \mathbb {R} ^{7}:\|x\|=r\right\}.}
V 7 = 16 π 3 r 7 105 {\displaystyle V_{7}={\frac {16\pi ^{3}r^{7}}{105}}}