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Printsmc
geometry senior
Problem
In , , , and . Point lies on , and bisects . Point lies on , and bisects . The bisectors intersect at . What is the ratio : ? 
(A)
(B)
(C)
(D)
Solution
By the angle bisector theorem, so Similarly, . There are two ways to solve from here. First way: Note that By the angle bisector theorem on Thus the answer is Second way: Now, we use mass points. Assign point a mass of . , so Similarly, will have a mass of So
Final answer
C