Geometry & Trigonometry
Intermediate

Space Diagonal of a Cuboid

Longest diagonal through a rectangular box.

Formula

d=l2+w2+h2d = \sqrt{l^2 + w^2 + h^2}

Variables

lLength
wWidth
hHeight

Example

A 1 × 2 × 2 box: d = √(1+4+4) = √9 = 3.

Did You Know?

The space diagonal of a box is the 3-D Pythagorean theorem — the longest straight line that fits inside.

cuboiddiagonal3d