# Definition:Euclid's Definitions - Book VI

Jump to navigation
Jump to search

## Euclid's Definitions: Book $\text{VI}$

These definitions appear at the start of Book $\text{VI}$ of Euclid's *The Elements*.

**Similar rectilineal figures**are such as have their angles severally equal and the sides about the equal angles proportional.- Two figures are
**reciprocally related**when there are in each of the two figures antecedent and consequent ratios. - A straight line is said to have been
**cut in extreme and mean ratio**when, as the whole line is to the greater segment, so is the greater to the less. - The
**height**of any figure is the perpendicular drawn from the vertex to the base.

## Sources

- 1926: Sir Thomas L. Heath:
*Euclid: The Thirteen Books of The Elements: Volume 2*(2nd ed.) ... (previous) ... (next): Book $\text{VI}$. Definitions