# Sectors and Segments difficult question, need helpWatch

#1
So I've been trying to attempt this question now, i know for a fact that I'm missing something in the process but i don't understand what it is.

What i did: found the arc length, found the area of the sector and tried to find the other side by using the cos rule which ended up being useless in the end
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#2
The question: https://gyazo.com/72795e483a3929baea3bd80a91f45eb5
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4 weeks ago
#3
Part a)? If that's the one you're stuck on then I'm guessing you're stuck finding BD? Consider similar shapes...

EDIT: BD is not required for part a).
Last edited by Notnek; 4 weeks ago
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#4
(Original post by Notnek)
Part a)? If that's the one you're stuck on then I'm guessing you're stuck finding BD? Consider similar shapes...
I mean I can see other shapes in there but i don't see how that helps.
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#5
(Original post by OJ Emporium)
I mean I can see other shapes in there but i don't see how that helps.
As in i don't really know what to do, feel like i've tried everything but im getting confused in the process.
Hell i'm not even sure whether that's actually a right angle in there or something else
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4 weeks ago
#6
(Original post by OJ Emporium)
As in i don't really know what to do, feel like i've tried everything but im getting confused in the process.
Hell i'm not even sure whether that's actually a right angle in there or something else
You're told that AC is a tangent to the circle so by a GCSE circle theorem, CAO must be a right-angle.

The aim is to find the shaded area which is the area of triangle CAO minus the area of the sector which I assume you've already found.

So that leaves the area of the triangle which can be found by 1/2 base x height where the base is 12cm. You're left with finding the height which is AC.

I hope I've given you enough to move you along. If you're still stuck, please post all your thoughts and working.

(Ignore what I said about similar shapes above - you don't need it for a))
Last edited by Notnek; 4 weeks ago
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#7
Yea noticed I missed out on that part and made corrections to that error, thanks man.
And dw i got the answer too.
Last edited by OJ Emporium; 4 weeks ago
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