Difference between revisions of "2009 AMC 8 Problems/Problem 20"

Revision as of 12:28, 14 August 2011

How many non-congruent triangles have vertices at three of the eight points in the array shown below?

$[asy]dot((0,0)); dot((0,.5)); dot((.5,0)); dot((.5,.5)); dot((1,0)); dot((1,.5)); dot((1.5,0)); dot((1.5,.5));[/asy]$

$\textbf{(A)}\ 5 \qquad \textbf{(B)}\ 6 \qquad \textbf{(C)}\ 7 \qquad \textbf{(D)}\ 8 \qquad \textbf{(E)}\ 9$

Revision as of 12:28, 14 August 2011 (view source) Mrdavid445 (talk \| contribs) (Created page with "How many non-congruent triangles have vertices at three of the eight points in the array shown below? <asy>dot((0,0)); dot((0,.5)); dot((.5,0)); dot((.5,.5)); dot((1,0)); dot((1...")		Revision as of 12:28, 14 August 2011 (view source) Mrdavid445 (talk \| contribs) Newer edit →
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		+	==Problem==
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	How many non-congruent triangles have vertices at three of the eight points in the array shown below?		How many non-congruent triangles have vertices at three of the eight points in the array shown below?