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ACT Math 4.3 Trigonometry 278 Views
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Description:
ACT Math: Trigonometry Drill 4, Problem 3. What is the length of side b?
Transcript
- 00:02
Here's your shmoop du jour...
- 00:05
The sin of angle A equals 4/9. What is the length of side B?
- 00:09
And here are your options...
- 00:13
We know that the sin of an angle equals the opposite side divided by the hypotenuse. Here,
- 00:18
the sin of A equals 4/9, which means that a = 4 and c = 9. Now we just need to find B
Full Transcript
- 00:24
We can do that by using the Pythagorean theorem...which
- 00:27
is A squared plus B squared equals C squared. We plug the values in, and get that 4 squared
- 00:32
plus B squared equals 9 squared. 16 plus B squared equals 81.
- 00:37
Subtract 16 from both sides, and we get that B squared equals 65.
- 00:42
Take the square root of both sides, and we have that B equals the square root of 65.
- 00:47
Which is answer choice C.
- 00:48
Easy.
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