Dw, glad you cleared things up actually. Is this for the grey circle or the black one? Cheers(Original post by RDKGames)
I have just looked over my working and realised I gave you nonsense as far as the grey part is concerned, got mixed up with it as I have done it a few days ago aha.
Allow me to clarify;
and you can work out with trigonometry therefore you can find the area of the smaller circle.
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