This was a new activity for me, and Kath will tell you, I felt exactly the same as you did. You could have used me as the visual.

I like the connection you made to claims and the conceptual build in your overview is logical and creative.

When I read dot point 6, Sometimes Never Always, I could anticipate some confusion due to the common misconceptions learners have.

My quick thinking is:

How about an activity something like …you get dealt a number of the Property cards and you have to draw a shape that satisfies all properties. It might be that you are in a pair and each of you pick one card. Both of you draw a shape that satisfies both cards without consulting and then compare and discuss. This could also work for bigger groups. It is a fluency task but might be a quick consolidation before you move onto the more complex considerations.

Thanks for sharing. I was 50-50 about using the task again but I will definitely do that now.

]]>I liked your question: what’s the most precise name we can give this shape?

It made me try and think of another way to phrase the question about trapeziums and parallelograms. They sound a bit like dad jokes.

eg What do you call a trapezium with two sets of parallel sides? A: a parallelogram.

Here’s some more:

What do you call a trapezium with two sets of parallel sides and a right angle?

What do you call a trapezium with 3 right angles?

What do you call a trapezium with two sets of parallel sides, a right angle and 2 adjacent sides of equal length?

What do you call a quadrilateral with 2 right angles and only one set of parallel sides?

As I wrote these I tried to think about the minimum info needed. It made me realise:

* that I could focus on different attributes but that some determined others.

* that there were multiple ways I could describe a shape.

* that there’s another attribute I relied on: internal angle sum of a quadrilateral is always 360 degrees.

I love that your blog post made me think differently about how I could approach teaching this. Thanks!

]]>A couple things I do that might or might not fit in. For elementary teachers, I think a lot of the work for learners is going from visual (van Hiele 0) to property (vH 1) reasoning. So we start with making quadrilaterals on GeoBoards and describing to someone to try to get them to make it to uncover some of the properties. The goofiest thing I do is slides from my quadrilateral vacation (https://www.slideshare.net/goldenj/my-quadrilateral-vacation2010) to get at our theme of variety of examples.

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