Jump to navigation Jump to search
The length $h$ of the line $AC$ is the height of the cone.
A right circular cone is a cone:
- whose base is a circle
- in which there is a line perpendicular to the base through its center which passes through the apex of the cone:
- which is made by having a right-angled triangle turning along one of the sides that form the right angle.
In the words of Euclid:
- When, one side of those about the right angle in a right-angled triangle remaining fixed, the triangle is carried round and restored again to the same position from which it began to be moved, the figure so comprehended is a cone.
And, if the straight line which remains fixed be equal to the remaining side about the right angle which is carried round, the cone will be right-angled; if less, obtuse-angled; and if greater, acute-angled.