Art of Problem Solving

2011 AIME II Problems/Problem 2: Difference between revisions

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Solution: (Needs better solution, I cannot remember exactly how I got the side length)
Solution: (Needs better solution, I cannot remember exactly how I got the side length)


Drawing the square and examining the given lengths, you find that the three segments cut the square into three equal horizontal sections (see diagram)
Drawing the square and examining the given lengths, you find that the three segments cut the square into three equal horizontal sections (see geoboard diagram [that thing is actually pretty cool])
Therefore, (x being the side length), <math>sqrt(x^2+(x/3)^2)=30</math>, or <math>x^2+(x/3)^2=900</math>. Solving for x, we get that x=9sqrt(10), and <math>x^2</math>=810
Therefore, (x being the side length), <math>sqrt(x^2+(x/3)^2)=30</math>, or <math>x^2+(x/3)^2=900</math>. Solving for x, we get that x=9sqrt(10), and <math>x^2</math>=810



Revision as of 21:49, 30 March 2011

Problem:

On square ABCD, point E lies on side AD and point F lies on side BC, so that BE=EF=FD=30. Find the area of the square ABCD.


Solution: (Needs better solution, I cannot remember exactly how I got the side length)

Drawing the square and examining the given lengths, you find that the three segments cut the square into three equal horizontal sections (see geoboard diagram [that thing is actually pretty cool]) Therefore, (x being the side length), $sqrt(x^2+(x/3)^2)=30$, or $x^2+(x/3)^2=900$. Solving for x, we get that x=9sqrt(10), and $x^2$=810

Area of the square is 810.

<geogebra>bb56f64482bd0dabba65a4dcad9d52a05d440f19</geogebra>