What is the measure of angle B in the triangle below?

Question

anonymous · Answer

attachment

e.mccormick · Answer

Know your trig ratios?

anonymous · Answer

like cos A etc?

e.mccormick · Answer

Yah.  Because you have a 90 degree angle, so that is known.  And two unknowns.  It has to be below 90 degrees, so it is acute.  The arc version of one of the ratios should find the angle.

anonymous · Answer

Could you help me figure it out

e.mccormick · Answer

It is angle B, so that top one.  Now, what is one of the ratios you know?  Sine?

anonymous · Answer

25/24

e.mccormick · Answer

oops...

anonymous · Answer

?

e.mccormick · Answer

sine = opposite over hypotenuse.  You got that up side down.

anonymous · Answer

oh yeah duh, i knew that just typed it wrong

anonymous · Answer

here are the answer choices A. 73.7°	

B. 90°	

C. 25.2°	

D. 16.3°

e.mccormick · Answer

Yah, it is easy to mess those up.  OK, so we have 

$\sin\theta = \dfrac{24}{25}$

Now, do you know how to get $\theta$ from that?

anonymous · Answer

no

e.mccormick · Answer

Apply arcsin AKA: $\sin^{-1}$

anonymous · Answer

so subtract 24/25 from 24/25??

e.mccormick · Answer

No, arcsine is a command on your calculator.

anonymous · Answer

oh, i dont have a calculator

e.mccormick · Answer

Google is a calculator.  =)

anonymous · Answer

so how would i word it on google?

anonymous · Answer

can i tell you what I think it is and you tell me if im right ?

e.mccormick · Answer

Because it is an equation, you do the same thing to both sides.

$\sin\theta = \dfrac{24}{25}\implies $
$\sin^{-1}(\sin\theta) = \sin^{-1}\left(\dfrac{24}{25} \right)\implies$
$\theta = \sin^{-1}\left(\dfrac{24}{25} \right)$

That last part is what you need to type into Google.  But you have to use ^ and ( ) and things like that.  So:

arcsin(24/25) in degrees

e.mccormick · Answer

If you don't tell it in degrees it does it in radians.

anonymous · Answer

ugh I can't figure out how to do it on google. Is the answer A, thats what I think it is

e.mccormick · Answer

https://www.google.com/search?q=+arcsin%2824%2F25%29+in+degrees

anonymous · Answer

ah thank you ") so i was right

e.mccormick · Answer

Yah. And now you know a bit of how to use Googl as a calculator. This talks about it more: http://www.googleguide.com/calculator.html That way you have a calculator that can do science stuff.

anonymous · Answer

Okay cool thank you :)

e.mccormick · Answer

np.  have fun!