POSSIBLY OF INTEREST TO OTHERS: Clarifying Quadrilaterals & Solids (LESSON 1)

Last Sunday afternoon I was lounging around watching TV whilst Carol was busy preparing a lesson plan for her primary-level maths class. The question came up... what actually are the subtle differences between quadrilaterals, squares, rectangles, oblongs, parallelograms, rhombus', trapezoids, trapeziums, kite shapes, diamond shapes... This discussion obviously lead to a trip to Google and Wikipedia but also spawned even more questions:

• Are self-intersecting quarilaterals still actually quadrilaterals?
• Should students be taught to recognise 3D shapes through 2D abstractions and should the commonly used isometric representations of 3D objects be termed "solids"?

OK - so I'm going to try and address some of these issues... but because this could be a long article I'm going to split it up into a number of separate "lessons".

LESSON 1:

I thought the best way to demonstrate the relationship between all of the different types of quadrilaterals would be through an "inheritance" diagram:

To help you understand it:
A Square inherits properties from both a Rhombus and Rectangle which in turn inherits properties from a parallelogram which is of course a Quadrilateral which is actually a type of Polygon.

So... A square is a:

• Rhombus
• Rectangle
• Parallelogram
• Quadrilateral
• Polygon

More fascinating quadrilateral info' coming in the next lesson...

PTX 0.3
- Over