Perpendicular drawn from a vertex of a triangle to the opposite side is called its altitude. There are three vertices in a triangle, so you can draw three of its altitudes.

In a triangle, the three altitudes pass through the same point, that is, they are concurrent. The point of concurrency is called the **Orthocentre of the triangle**.

Orthocentre will be

- in the interior of the triangle for an acute triangle
- in the exterior of the triangle for an obtuse triangle
- at the vertex containing the right angle for a right triangle