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Angles question help

image.jpgApparently y is 149* but I don't understand why! Please could someone explain how you would work this out, thankyou!
Reply 1
Avatar for rm715
rm715
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Original post by rm715
y is 149* but I don't understand why!

Lol I did a pun and I didn't notice
Reply 2
Avatar for B_9710
B_9710
18
Interior angles in a hexagon add up to 720.
Yeah, interior angles add up to 720, subtract all of those angles from 720 to give 149.

Also, to work out the sum of the interior angles, you do (n-2) x 180 (because you can split the shape into triangles, technically).
Reply 4
Avatar for rm715
rm715
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Ahh I get it, thankyou. So a hexagon's interior is just 360x2
Reply 5
Avatar for Zacken
Zacken
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Original post by rm715
Ahh I get it, thankyou. So a hexagon's interior is just 360x2


The sum of the interior angles of an nn sided polygon is (n−2)×180circ(n-2) \times 180^{circ}. In this case, n=6n=6 so (6−2)×180∘=4×180∘=2×360∘=720∘(6-2) \times 180^{\circ} = 4\times 180^{\circ} = 2 \times 360^{\circ} = 720^{\circ}.
Reply 6
Avatar for Notnek
Notnek
21
Original post by rm715
Ahh I get it, thankyou. So a hexagon's interior is just 360x2

Now you can try beating the Eggheads to test your understanding:

Reply 7
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rm715
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Original post by notnek
Now you can try beating the Eggheads to test your understanding:



I thought it was a dodecagon :frown: why did I get it wrong
Reply 8
Avatar for Notnek
Notnek
21
Original post by rm715
I thought it was a dodecagon :frown: why did I get it wrong

The formula to find the sum of the interior angles of a polygon is

Sum = ( Number of sides - 2 ) x 180

A dodecagon has 12 sides. So for a dodecagon :

Sum = (12 - 2) x 180 = 10 x 180 = 1800.

So it can't be a dodecagon.


By the way, the use of the word 'regular' in this question is unnecessary. Non-regular polygons have the same sum as regular polygons.
(edited 8 years ago)

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