# Generalising and comparing generalisations

## Lesson details

### Key learning points

1. In this lesson, we will combine everything learnt so far about angles in polygons to compare how specific examples relate to generalised cases.

### Licence

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## Video

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## Worksheet

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## Starter quiz

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### 5 Questions

Q1.
The mean interior angle of a quadrilateral is...
180 degrees
360 degrees
45 degrees
Q2.
The mean exterior angle of a pentagon is...
108 degrees
360 degrees
60 degrees
Q3.
If I have a regular polygon with an exterior angle of 5 degrees, how many sides does my polygon have?
36 sides
5 sides
50 sides
Q4.
A square would have both an interior and exterior angle of 90 degrees
False
Q5.
If I had a shape with 180 sides, what would the mean exterior angle be?
180 degrees
3 degrees
4 degrees

## Exit quiz

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### 5 Questions

Q1.
The exterior angles of a hexagon sum to 540 degrees.
True
Q2.
A triangle ALWAYS has each exterior angle as 60 degrees.
True
Q3.
The general formula for working out the mean exterior angle of an n-sided polygon is...
180(n-2)
360
n/360
Q4.
The calculation to work out the sum of the interior angles for an octagon would be...
180 x n
360 x
360(8 - 2)
Q5.
180n - 360 is a generalisation that tells us the...
Sum of the angles around a point
Sum of the angles on a straight line
Sum of the total exterior angles of a polygon
Correct answer: Sum of the total interior angles of a polygon