Question

So, on my right triangle triangle I have here, they give all the sides and are asking for an angle

The sides are
Opp=15
Adj=8
Hyp=17

And we are looking for the x angle.

Answer 1

Do you know SOHCAHTOA?

Your sine, cosine, and tangent laws?

Answer 2

Yes

Answer 3

Okay, since you know all three side lengths, you can use any of the three functions to determine x.

Answer 4

For example, \(\sin x = \frac{\text{opp}}{\text{hyp}}\)

Answer 5

And that is it? Just use 17 over 15 ,divide and my answer would be 1.13?

Answer 6

It's not x = 1.13. It's sin x = 1.13.

Answer 7

Ah, sorry for not using correct mathematical vocabulary.

Answer 8

No, that's not my point. The point is, you need to solve for x. Right now, you only know sin x.

Answer 9

You need to get rid of the sin.

Answer 10

Oh? How is this done?

Answer 11

One thing first. It's not 17/15, it's 15/17.

Answer 12

Got it

Answer 13

So, \(\sin x = \frac{15}{17} = 0.882\)

Answer 14

To get rid of the sin, you calculate \(\sin^{-1}\). On your calculator, you should have a way to do this.

Answer 15

So, \(x = \sin^{-1} (\frac{15}{17})\)

Answer 16

I did not know there was such an option? Thank you.

Answer 17

You might need to hit something like 2nd function, or inverse, then hit sin.

Answer 18

You should end up with something around 60 degrees, if it's sine of 15/17.

Answer 19

This isn't my outcome, I get a decimal of 1.001

Answer 20

Okay, so you took your amount (0.882) and hit inverse sine (sin^-1) and got 1.001?

Answer 21

Oh but wait, that is sin(h), Sorry, personal mistake.

Answer 22

No worries.

Answer 23

Since you knew all the sides, you could have also done \(x = \cos^{-1} (\frac{8}{17})\) or \(x = \tan^{-1} (\frac{15}{8})\), and gotten identical answers.

Answer 24

Odd, I get the decimal of 0.795, how does this lead to 60 degrees?

Answer 25

What calculation gives you 0.795?

Answer 26

Well, seeing as I'm using the computer based calculator, this may have swayed my calculation. When typed in, it shows up as *asinh(15 /17)*

Answer 27

Where did you type that in?

Answer 28

But lo, I have found my answer as you have predicted, thank you so much kind sir, It was simply a typing error.

Answer 29

http://www.wolframalpha.com/input/?i=sin%5E-1%280.882%29

Answer 30

Good stuff! You're very welcome. :)

Answer 31

I shall be on my way! Good day to you, and thank you for your time.

Answer 32

You too, David! Cheers!