Difference between revisions of "2002 AMC 10A Problems/Problem 8"

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==Problem==
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#redirect [[2002 AMC 12A Problems/Problem 8]]
Betsy designed a flag using blue triangles, small white squares, and a red center square, as shown. Let <math>B</math> be the total area of the blue triangles, <math>W</math> the total area of the white squares, and <math>R</math> the area of the red square. Which of the following is correct?
 
 
 
<asy>
 
unitsize(3mm);
 
fill((-4,-4)--(-4,4)--(4,4)--(4,-4)--cycle,blue);
 
fill((-2,-2)--(-2,2)--(2,2)--(2,-2)--cycle,red);
 
path onewhite=(-3,3)--(-2,4)--(-1,3)--(-2,2)--(-3,3)--(-1,3)--(0,4)--(1,3)--(0,2)--(-1,3)--(1,3)--(2,4)--(3,3)--(2,2)--(1,3)--cycle;
 
path divider=(-2,2)--(-3,3)--cycle;
 
fill(onewhite,white);
 
fill(rotate(90)*onewhite,white);
 
fill(rotate(180)*onewhite,white);
 
fill(rotate(270)*onewhite,white);
 
</asy>
 
 
<math>\text{(A)}\ B = W \qquad \text{(B)}\ W = R \qquad \text{(C)}\ B = R \qquad \text{(D)}\ 3B = 2R \qquad \text{(E)}\ 2R = W</math>
 
 
 
==Solution==
 
The blue that's touching the center red square makes up 8 triangles, or 4 squares. Each of the corners is 2 squares and each of the edges is 1, totaling 12 squares. There are 12 white squares, thus we have <math>\boxed{B=W\Rightarrow \text{(A)}}</math>.
 
 
 
==See Also==
 
{{AMC10 box|year=2002|ab=A|num-b=7|num-a=9}}
 
 
 
[[Category:Introductory Geometry Problems]]
 

Latest revision as of 15:35, 18 February 2009