# T4 maths exterior sides

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#1

Can anyone explain this question. Answer is 15. Not sure what the question is asking.
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3 years ago
#2
When you walk all the way round the exterior of a polygon, pointing your arm out in front of you, you will see that your arm turns through 360 degrees. It only turns through an angle when you get to a vertex, a point where two sides meet.

If the polygon has 8 equal external sides, then it also has 8 equal external angles (i.e. the angles made between each of the external sides). So if the size of the external angle is , then we must have from which we can find .

In your case, you can find the external angle for the shape by geometry, but you need to find the number of sides , say. Can you finish this? You need to write down an equation similar to the one I gave above, then solve it.
0
3 years ago
#3
you need to find the acute angles in the trapezia. then find the internal angle of the big polygon.... then the external angle.... then the number of sides.
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#4
So the tiles continue to form a full circle? I understand now I think.
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