Difference between revisions of "2005 AMC 10A Problems/Problem 23"

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BCDE is a square. Point A is chosen outside of BCDE suck that angle BAC= 120 and AB=AC. Point F is chosen inside BCDE such that the triangles ABC and FCD are congruent. If AF=20, compute the area of BCDE.  
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BCDE is a square. Point A is chosen outside of BCDE such that angle BAC= 120 and AB=AC. Point F is chosen inside BCDE such that the triangles ABC and FCD are congruent. If AF=20, compute the area of BCDE.  
  
 
(A)1/6 (B) 1/4 (C) 1/3 (D) 1/2 (E)2/3
 
(A)1/6 (B) 1/4 (C) 1/3 (D) 1/2 (E)2/3

Revision as of 13:23, 14 February 2007

BCDE is a square. Point A is chosen outside of BCDE such that angle BAC= 120 and AB=AC. Point F is chosen inside BCDE such that the triangles ABC and FCD are congruent. If AF=20, compute the area of BCDE.

(A)1/6 (B) 1/4 (C) 1/3 (D) 1/2 (E)2/3