ShmoopTube

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Here’s your shmoop du jour, brought to you by straws.

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In our opinion, they totally suck.

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An equilateral triangle can be made using three straws.

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Two congruent equilateral triangles can be made using five straws.

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What is the smallest number of straws needed to make six congruent equilateral triangles?

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And here are the potential answers...

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Okay, first of all…while we appreciate the effort, you can put the box of straws back where you found them.

00:32

We don’t need to be that…hands on.

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Okay, they show us the triangle made out of three straws, and then the two triangles made out of 5.

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The question asks us what is the least number of straws we can use to make six of these puppies?

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Well, we could lay them all out in a row… that would be one way of doing it.

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That would take… 13 total straws.

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But… we have a sneaking feeling they’re looking for a trickier answer than that.

00:54

How else can we arrange these fellas?

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All right… so if we keep adding them in a clockwise or counterclockwise direction instead…

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…we wind up with a hexagon that appears to be divided into 6 equal pieces.

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And that way, we only need a single straw to complete our final triangle…

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…giving us a grand total of 12, which is unbeatable.

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So our solution is choice B.

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