Altitudes of a Triangle

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

1. in the interior of the triangle for an acute triangle
2. in the exterior of the triangle for an obtuse triangle
3. at the vertex containing the right angle for a right triangle