Definition:Space Diagonal

Definition

Consider a parallelepiped $P$.

The space diagonals of $P$ are the line segments that can be drawn from each vertex $X$ of $P$ to the vertex $Y$ of $P$ which is not contained in any of the faces of $P$ which contain $X$.

In the above diagram, the space diagonals of the parallelepiped $ABCDEFGH$ are $AF$, $BE$, $CH$ and $DG$.

Sources

• Weisstein, Eric W. "Space Diagonal." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SpaceDiagonal.html