Term 2 Week 5

Geometry can get very complex - a 2d representation of a 4 dimensional 'polygon' ('polychora')

This week we are exploring the nature of angles in many sided figures (polygons)

By dividing 4 sided figures (quadrilaterals) into two triangles we understand that the internal angles add up to the same as that of two triangles - ie 360 degrees.

By doing the process for 5 sided figures we get 3 triangles - ie 540 degrees

We quickly discover that there is a pattern here - the internal angles of a shape with any number of sides always add up to 180 x (number of sides - 2) degrees.

So for example we can now work out that all 20 sided figures have internal angle sum of 180 x (20 - 2) degrees - ie 3240 degrees.

After getting familiar with solving these problems we will have a topic test early next week.

Investigative Geometry Assignment 2 is here
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