Question 902511
Consider a pole running from one corner to the farthest corner of a box. 
In 3D space the start of the pole would be at (0,0,0). 
The endpoint would be at (12,2,2).
Use the distance formula,
{{{D^2=(x[1]-x[2])^2+(y[1]-y[2])^2+(z[1]-z[2])^2}}}
{{{D^2=(12-0)^2+(2-0)^2+(2-0)^2}}}
{{{D^2=144+4+4}}}
{{{D^2=152}}}
{{{D=2sqrt(38)}}}