# Definition:Triangle (Geometry)/Height

## Definition

The height of a triangle is the length of a perpendicular from the apex to whichever side has been chosen as its base.

That is, the length of the altitude so defined.

Thus the length of the altitude $h_a$ so constructed is called the height of $\triangle ABC$.

## Also known as

The height of a triangle is otherwise known as its altitude.

However, it is preferred on $\mathsf{Pr} \infty \mathsf{fWiki}$ that the terms height and altitude are kept strictly separate.