Tricylinder
= Tricylinder
{title2=$x^2+y^2\leq a^2,\quad y^2+z^2\leq a^2,\quad z^2+x^2\leq a^2$}
The common intersection of three equal-radius <circular cylinders> with mutually perpendicular axes. The displayed inequalities describe a centered example of radius $a$. It is a <Steinmetz solid>; its <surface area> is given by the <surface area of a tricylinder> formula.