The area of a triangle can be calculated with the equation:


$ area = \frac {1}{2}\times base length \times perpendicular height $

or Area1

However, this formula is only useful if the the base length and the perpendicular height to the base are known. There is another method for finding the area of a triangle if two side lengths are known (a and b) and the angle between them (C). (See Trigonometry for naming triangles). The formula is:


These are the only two ways of finding the area of a triangle needed for GCSE or iGCSE, though there are many more (at least 7 ways in total!)