Triangle is one of the basic shapes geometry polygon edges and three. It could also be stated as a closed figure formed by joining the three non collinear points.

Consider the figure shown below.

The points A,B and C are called vertices of the triangle. It has three sides, AB, BC and CA. It has three angles, ,

Altitude of a triangle

An altitude of an triangle is the line segment drawn perpendicular from the vertex of a triangle to it opposite side.

Median of a triangle

A Line segment joining the vertex of the triangle to the midpoint of the opposite side is called the median. In the figure above, we have AD, BE, CF as medians. They cross at one point named G. Therefore we say, medians of a triangle are concurrent.