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mathmath333
 one year ago
Counting question
mathmath333
 one year ago
Counting question

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mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0dw:1440718821577:dw

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0\(\large \color{black}{\begin{align} & \normalsize \text{Find the number of rectangles.}\hspace{.33em}\\~\\ \end{align}}\)

mathmath333
 one year ago
Best ResponseYou've already chosen the best response.0the lines are perpendicular to each other.

ChillOut
 one year ago
Best ResponseYou've already chosen the best response.4Begin by choosing two pairs of horizontal lines and two pairs of vertical lines so you can have a rectangle.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I just know theres a ton

ChillOut
 one year ago
Best ResponseYou've already chosen the best response.4Let \(\left(\begin{matrix}a \\ 2\end{matrix}\right)\) be the number of vertical lines that can be picked, and \(\left(\begin{matrix}b \\ 2\end{matrix}\right)\) the number of horizontal lines that can be picked. For each pair of horizontal lines, there's a pair of vertical lines that will form a rectangle with them. Therefore you have \(\left(\begin{matrix}n \\ 2\end{matrix}\right)\)*\(\left(\begin{matrix}b \\ 2\end{matrix}\right)\) as the number of rectangles.

ChillOut
 one year ago
Best ResponseYou've already chosen the best response.4That would be my guess :)

ChillOut
 one year ago
Best ResponseYou've already chosen the best response.4Yes. And sorry, meant to be "a" in the last line.

ChillOut
 one year ago
Best ResponseYou've already chosen the best response.4No problem, do you have an answer to the problem?
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