| Area of a Triangle There are several ways to find the area of a triangle. One of them is the well known "half base times height" formula taught at school. A more general form of this, working directly from two sides of the triangle and the angle between them, is the method below. (Another, which works from the lengths of the three sides, is known as Heron's Formula.) For the "two sides and an angle" method, start with a general triangle. The angles are labelled P, Q & R and the sides opposite them labelled p, q & r like this: 
If A = area of the triangle, then: 
Most recently updated at 18:29 (British time) on 07 April 2004 |