ShmoopTube

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Here’s your shmoop du jour, brought to you by isosceles triangles. I came, I saw, I sosceles.

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Triangle ACD is an isosceles triangle, and CD is parallel to BE.

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What is the perimeter of triangle ABE?

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Here are the potential answers...

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Okay, so times are hard, and there’s a mad cheese shortage.

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So…we have to leave out a smaller hunk of cheese to catch that mouse who’s been running

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around our office like he owns the place…

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Okay, our cheese triangle needs a downgrade. Now… because we’re told that CD is parallel

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to BE, we know that triangles ABE and ACD are similar.

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We’re also told that ACD is an isosceles triangle… and because all similar triangles

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maintain the same proportions, we know that ABE is isosceles as well.

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And THAT means that sides AD and AC are equal.

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We can subtract the 6 they give us from 16 to get a side length

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for AB of 10… which is also the length of AE.

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And it’s mere addition from here to get our perimeter… 10 plus 10 plus 8 is 28…

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…Answer is B. As in “brie.”

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