Look at the figure.

What is the distance, in meters, between point B and point C?

Question

Look at the figure.
 


What is the distance, in meters, between point B and point C?

anonymous · Answer

attachment

.sam. · Answer

Use cosine

anonymous · Answer

Use cosine bro

anonymous · Answer

cosine

anonymous · Answer

How do you know?

mertsj · Answer

You know the side adjacent the given angle right?

anonymous · Answer

that angle

.sam. · Answer

$$\cos(x)=\frac{\text{adjacent}}{\text{hypotenuse}}$$

anonymous · Answer

Yeah

anonymous · Answer

the angle

mertsj · Answer

And you are trying to find the hypotenuse, right?

anonymous · Answer

COS --> CAH

where 
A= adjacent side
H= Hypotnus

anonymous · Answer

So you use w.e according to what is given? Cause i never understood this...

mertsj · Answer

Yes.  You look at what is given and what you are trying to find and try to pick the function that contains these quantities.

anonymous · Answer

sin    --->SOH
cos    --->CAH
tan    --->TOA

anonymous · Answer

O=opposite side
A=adjacent side
H=hypotenuse

mertsj · Answer

So, using the cosine function and the given information, what equation would you write?

anonymous · Answer

but is it A or C and how would i know? i took notes asked the teacher and that didn't help

mertsj · Answer

Can you answer my question above?

anonymous · Answer

Yeah so cosine A/H So 35/? right?

anonymous · Answer

wait i mean 200/?

mathteacher1729 · Answer

|dw:1338424393698:dw|

Cos(of the 35 degrees) = adjacent side (of the 35 degree angle)  divided by the hypotenuse (which is always opposite the right angle). 

So 

cos(35) = 200/x

But we want x...

so multiply both sides by x

x * cos(35) = 200     now divide by cos(35)

x = 200/cos(35)

The important thing... the REALLY IMPORTANT thing here, that many people get confused about is that cos(35) is just a number. 

So that's that. :)