Definition:Right Circular Cone/Axis

Definition

Let $K$ be a right circular cone.

Let point $A$ be the apex of $K$.

Let point $O$ be the center of the base of $K$.

Then the line $AO$ is the axis of $K$.

In the words of Euclid:

The axis of the cone is the straight line which remains fixed and about which the triangle is turned.

(The Elements: Book $\text{XI}$: Definition $19$)

Linguistic Note

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

Compare basis.

Sources

• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): axis (of a cone)
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): cone