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Sine is the opposite over the hypotenuse; cosine is the adjacent over the hypotenuse; and tangent is the opposite side over the adjacent side....
FYI: cats don't like to get wet. Okay, so that fact won't be relevant every time you solve trig equations, but it happens to be this time.
SAT Math 10.4 Geometry and Measurement 380 Views
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Description:
SAT Math 10.4 Geometry and Measurement. What is the perimeter of triangle DEF?
- Triangles / Similar Triangles
- Product Type / SAT Math
- Geometry / Similarity, right triangles, trigonometry, and dimensions
- Geometry / Understand similarity in terms of similarity transformations
- Similarity, Right Triangles, and Trigonometry / Understand similarity in terms of transformations
- Additional Topics in Math / Congruence and similarity
Transcript
- 00:02
Here’s your shmoop du jour, brought to you by similar triangles.
- 00:07
If it wasn’t for the tattoo, we wouldn’t be able to tell them apart.
- 00:10
Triangle ABC is similar to triangle DEF. What is the perimeter of triangle DEF?
- 00:18
Okay, we’ve got a couple of similar triangles here.
- 00:21
Apparently triangles of a feather flock together...
Full Transcript
- 00:24
All right, so these are both right triangles…
- 00:26
…and one of them has a leg with length 6 and a hypotenuse with length 10…
- 00:31
…Hello! Looks like we’ve got a 3-4-5 triangle...
- 00:35
Both known distances have been doubled from the original 3-4-5 ratio…
- 00:39
…so we know we have to double the missing length as well.
- 00:43
Four times two is eight… and we have a triangle with sides of 6, 8 and 10.
- 00:50
Plugging those numbers into our internal adding machine… we get a total perimeter of 24.
- 00:55
Now, before you waste gobs of time trying to figure out what the lengths of the sides in our other triangle are…
- 01:01
…just note that the one side we DO know is 2/3 of the corresponding side in triangle number one.
- 01:07
These triangles are similar… so the perimeter is going to carry over the same ratio.
- 01:12
We’ll take 24 times 2/3… to get 16…and that’s our answer. We're done!
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