2010 UNCO Math Contest II Problems/Problem 11
Revision as of 20:18, 19 October 2014 by Timneh (talk | contribs) (moved 2010 UNC Math Contest II Problems/Problem 11 to 2010 UNCO Math Contest II Problems/Problem 11: disambiguation of University of Northern Colorado with University of North Carolina)
Problem
(a) The 
square grid has 
dots equally
spaced. How many squares (of all sizes)
can you make using four of these dots
as vertices? Two examples are shown.
![[asy] for (int x=0; x<3; ++x) {for (int y=0; y<3; ++y) {dot((x,y));dot((x+4,y));} } draw((0,0)--(1,0)--(1,1)--(0,1)--cycle,black); draw((4,1)--(5,0)--(6,1)--(5,2)--cycle,black); draw((3,-1)--(3,3),dashed); [/asy]](http://latex.artofproblemsolving.com/2/5/c/25cf0db35690d9453f4c01ff44569a8e74957ba1.png)
(b) How many for a 
?
(c) How many for a 
?
(d) How many for an 
grid of dots?
