If ABCD is a regular tetrahedron with length of any edge be 7, then

Volume of tetrahedron is  $\frac{343}{6\sqrt{2}}$

Volume to tetrahedron is  $\frac{243}{\sqrt{2}}$

Minimum distance of any vertex from the opposite face is  $7\sqrt{\frac{3}{2}}$

Minimum distance of any vertex from the opposite face is  $7\sqrt{\frac{2}{3}}$