Hi,

There are quite a few ways to find the area of a triangle. Which expression you use depends on what you know about the triangle.

The expression students usually see first is that the area of a triangle is

\[\mbox{ triangle area } = \frac12 \times \mbox{ base } \times \mbox{ height.}\]

This is useful if you know or can easily find the length of the base and the height.

If you know the lengths of the three sides of the triangle you can use Heron's Formula.

If you go to the Quandaries and Queries page on Math Central and search for the phrase area of a triangle you will see you will see a number of questions we have received on the area of a triangle and how we have responded to them.

There is also a nice list of formulas is given on the mathworld site:

http://mathworld.wolfram.com/TriangleArea.html.

Penny