Description/Aim

Its one thing to (think you) know the properties of all the quadrilaterals its another to describe their defining properties in as few 'moves' as possible. In this activity, you are asked to construct 'indestructible' shapes using dynamic geometry. You have to decide on the defining properties and use them to build the shapes like the trapezium/trapezoid to the left!

Please find below the instructions and record sheet and exmaples of what your finished work might look like!

Time 1- 2 hours Age 13+

Why we like this activity ….

This topic appears frequently during secondary mathematics from 11 year olds looking at properties of
symmetry, to 16 year olds studying set theory, defining subsets of quadrilaterals etc. To complete this
task, you really have to be on top of your properties of quadrilaterals and pull in other aspects of
geometry in order to construct them! Definitely HOT (Higher Order Thinking)

How this activity be used ….

Obviously you need dynamic geometry software and access to computers. Geogebra is open source free
dynamic geometry software. The activity works better if each individual has their own computer.

What to expect when using this activity – from our experience

Experimentation is the answer! Some students might be premature in concluding they have constructed
the shape, so it is helpful to ask students to analyse critically each others work so that they can see
the limitations of their constructions if there are any.

Extra Notes

Try also; 'Sets of Quadrilaterals' and 'Properties of Quadrilaterals'

Written by Jim Noble 25/03/09