# Definition:Cylinder/Axis

(Redirected from Definition:Axis of Cylinder)

## Definition

In the words of Euclid:

The axis of the cylinder is the straight line which remains fixed and about which the parallelogram is turned.

In the above diagram, the axis of the cylinder $ACBEFD$ is the straight line $GH$.

## Linguistic Note

The plural of axis is axes, which is pronounced ax-eez not ax-iz.

Compare basis.