don steward
mathematics teaching 10 ~ 16

Friday, 3 May 2013

angles in polygons by chopping

what do you see here?

and here?

instead: students could try to create their own shapes using four of the 30, 60, 90 triangles
or they could use the sheet then try to create some more

an intention is that they sum the angles at the corners to explore the angle sums of various polygons
in the above resources the triangles' vertices do not all meet at the vertices of the polygons

so students will need to work out the angle sums of the polygons by deciding which of the 30, 60, 90 angles to use and which not to use

for the following resources, the vertices of the 30, 60, 90 triangles are all at the vertices of the polygons 

I think these are all the options for quadrilaterals and pentagons
I don't think this is all the options for hexagons (I gave up)

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