• Geometry: Symmetry, Reflection
A Geomirror is a translucent piece of plastic about 9 cm by 15 cm. One of the 15 cm edges is rebated. When using a Geomirror the rebated edge must always be placed downwards and facing the user. The Geomirror is held upright by two ends, which in the case of a Geomirror are mirrors. The geomirror may be used to determine lines of symmetry.
![](http://mathsmaterials.com/wp-content/uploads/2019/12/56-31980.jpg)
Mathematical Language
Line of symmetry, reflection, symmetry.
Using A Geomirror
While holding the two ends the Geomirror can be placed perpendicular to the shape being examined. The Geomirror is the ideal tool for testing whether a shape has a line or lines of symmetry.
![](http://mathsmaterials.com/wp-content/uploads/2019/12/56-01-1024x697.jpg)
Typical classroom Requirements
A class set:
~16 Geomirrors
Ideally one Geomirror per pair of students, but one Geomirror per group of four students would be sufficient.
Support and Complementary Materials
![](http://mathsmaterials.com/wp-content/uploads/2019/12/57-22243-5.jpg)
![](http://mathsmaterials.com/wp-content/uploads/2019/12/57-22243-2.jpg)
![](http://mathsmaterials.com/wp-content/uploads/2019/12/57-22243-1.jpg)