2018 AMC 12A Problem 20


Triangle ABCABC is an isosceles right triangle with AB=AC=3AB=AC=3 . Let MM be the midpoint of hypotenuse BC\overline{BC} . Points II and EE lie on sides AC\overline{AC} and AB\overline{AB} , respectively, so that AI>AEAI>AE and AIMEAIME is a cyclic quadrilateral. Given that triangle EMIEMI has area 22 , the length CICI can be written as abc\frac{a-\sqrt{b}}{c} , where aa , bb , and cc are positive integers and bb is not divisible by the square of any prime. What is the value of a+b+ca+b+c ?

(A) 9(B) 10(C) 11(D) 12(E) 13\textbf{(A) }9 \qquad\textbf{(B) }10 \qquad\textbf{(C) }11 \qquad\textbf{(D) }12 \qquad\textbf{(E) }13 \qquad


Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.

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Category: AMC 12A
Points: 3
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