A directory of useful objects found on the web for teaching Maths.

uses formulas to calculate the areas of quadrilaterals and circles, and converts between units of area

- GeoGebra HowTo: Construct a Rhombus
- GeoGebra, Tutorial | PDF
- Perimeter and Area - diagram library
- Image, Diagram Library | Image: PNG
- The area of a triangle
- Explanation | PDF