Math CentralQuandaries & Queries


Question from reg, a student:

Hi, i have been given an irregular pentagon in which i have to work out the area.
I have been told to make three triangles and then work out the area of these triangles and then add them up.

I require your help because i have the length of two sides of one of the triangle - how do i work out the other side?

I have not been provided with any angles - can i make the angles up?

Please help me???

Hi Reg,

You need to know something else about the pentagon. If you only have the lengths of the sides then you can construct pentagons of different shapes and different areas with these side lengths. Do you know something else? Do you know the angles or the lngth of a diagonal?


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS