tianzhu:Thanks Tianzhu for the answer. My dd couldn't figure out the working thus no answer for this.lesskiasu:Hi, can anyone help on to this question? The question is Catholic High Prelim 2011.
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Hi
Students are requested to leave their answers in terms of pi.
Apply the formula for calculating the area of a semi circle, and you should get an answer of 12.5pi.
Best wishes
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Will get her do it next time to post the question together with the answer.
:thankyou: