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# Can anyone explain this maths IGCSE question? watch

1. The total area of the following shape is X.
The area of the shaded part of each shape is kX.

Find the value of k.

Attachment 516873

the mark scheme:
*view attachment*

I got that the sector area is: 1/4 x Pi x r^2
And that the shaded area is: (1/4 x Pi x r^2) - (1/2 x r^2)

I don't understand how you get k.
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2. (Original post by SuchBants)
The total area of the following shape is X.
The area of the shaded part of each shape is kX.

Find the value of k.

Attachment 516873

the mark scheme:
*view attachment*

I got that the sector area is: 1/4 x Pi x r^2
And that the shaded area is: (1/4 x Pi x r^2) - (1/2 x r^2)

I don't understand how you get k.
So sector area is X then shaded area is kX

therefore: the r's cancel.
3. (Original post by Zacken)
So sector area is X then shaded area is kX

therefore: the r's cancel.
I understand how the area of the shaded is ..k(1/4) x Pi x r^2

but what is the left side? r^2(Pi/4 - 1/2)
4. (Original post by SuchBants)
I understand how the area of the shaded is ..k(1/4) x Pi x r^2

but what is the left side? r^2(Pi/4 - 1/2)
Factorise out of .
5. (Original post by Zacken)
Factorise out of .
Got it, thanks
6. (Original post by SuchBants)
Got it, thanks
No problem.

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