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SAT Math 2.5 Geometry and Measurement 258 Views
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Description:
SAT Math 2.5 Geometry and Measurement
Transcript
- 00:02
Here’s your shmoop du jour, brought to you by isosceles triangles. I came, I saw, I sosceles.
- 00:11
Triangle ACD is an isosceles triangle, and CD is parallel to BE.
- 00:16
What is the perimeter of triangle ABE?
- 00:20
Here are the potential answers...
- 00:24
Okay, so times are hard, and there’s a mad cheese shortage.
Full Transcript
- 00:27
So…we have to leave out a smaller hunk of cheese to catch that mouse who’s been running
- 00:31
around our office like he owns the place…
- 00:33
Okay, our cheese triangle needs a downgrade. Now… because we’re told that CD is parallel
- 00:37
to BE, we know that triangles ABE and ACD are similar.
- 00:42
We’re also told that ACD is an isosceles triangle… and because all similar triangles
- 00:47
maintain the same proportions, we know that ABE is isosceles as well.
- 00:52
And THAT means that sides AD and AC are equal.
- 00:58
We can subtract the 6 they give us from 16 to get a side length
- 01:01
for AB of 10… which is also the length of AE.
- 01:06
And it’s mere addition from here to get our perimeter… 10 plus 10 plus 8 is 28…
- 01:10
…Answer is B. As in “brie.”
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