Difference between revisions of "2012 AMC 10B Problems/Problem 14"
Line 7: | Line 7: | ||
Thus, answer choice D is correct. | Thus, answer choice D is correct. | ||
+ | {{MAA Notice}} |
Revision as of 12:15, 4 July 2013
Solution
Observe that the rhombus is made up of two congruent equilateral triangles with side length equal to GF. Since AE has length and triangle AEF is a 30-60-90 triangle, it follows that EF has length 1. By symmetry, HG also has length 1. Thus GF has length . The formula for the area of an equilateral triangle of length s is . It follows that the area of the rhombus is:
Thus, answer choice D is correct. The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions.