MathDB
Another geometry with equilateral triangle

Source: 2006 AIME II 6

March 28, 2006
geometrytrigonometryAMCAIMEUSA(J)MOUSAMOsimilar triangles

Problem Statement

Square ABCDABCD has sides of length 1. Points EE and FF are on BC\overline{BC} and CD\overline{CD}, respectively, so that AEF\triangle AEF is equilateral. A square with vertex BB has sides that are parallel to those of ABCDABCD and a vertex on AE\overline{AE}. The length of a side of this smaller square is abc\displaystyle \frac{a-\sqrt{b}}{c}, where aa, bb, and cc are positive integers and bb is not divisible by the square of any prime. Find a+b+ca+b+c.