Bicylinder
= Bicylinder
{title2=$V=16a^3/3$}
The solid intersection of two equal-radius infinite <circular cylinders> whose axes meet at a right angle. For radius $a$, the <cross section> at height $z$ along the common perpendicular coordinate is a <square> of <area> $4(a^2-z^2)$, so its <volume> is $16a^3/3$.