Triangles ratio
Public  10/01/17  5xp  Math  40.0% 
ABC is an equilateral triangle. DEF is another equilateral triangle with its two vertices (E, F) on the circumcircle of ABC and its third vertex (D) on the AB segment. O is the circumcenter of ABC. What is the ratio area(ABC)/area(DEF)? Answer format: number rounded to 5 digits after the decimal point.
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