+0  
 
+2
1385
3
avatar+476 

Please help! Iḿ stuck! (thereś an image, please open)

 May 22, 2017
edited by ZZZZZZ  May 22, 2017

Best Answer 

 #1
avatar+9479 
+2

Here I made a triangle where A is the first sighting, B is the light, and C is the second sighting.

The question is, what is the length of BC ?

 

On this first one, I just focused on the angles.

 

m∠BAC = 107º - 60º   =   47º

measure of the green angle = 180º - 107º   =   73º

 

Since the two vertical lines are parallel and line AC crosses them, we have two parallel lines cut by a transversal. So.. the two green angles are the same.

 

Now let's just look at the second triangle.

We can use law of sines to find BC.

\(\frac{1.5}{\sin 26}=\frac{BC}{\sin 47} \\~\\ \frac{1.5}{\sin 26}*\sin 47 =BC \\~\\ 2.503\text{ km} \approx BC\)

 May 23, 2017
 #1
avatar+9479 
+2
Best Answer

Here I made a triangle where A is the first sighting, B is the light, and C is the second sighting.

The question is, what is the length of BC ?

 

On this first one, I just focused on the angles.

 

m∠BAC = 107º - 60º   =   47º

measure of the green angle = 180º - 107º   =   73º

 

Since the two vertical lines are parallel and line AC crosses them, we have two parallel lines cut by a transversal. So.. the two green angles are the same.

 

Now let's just look at the second triangle.

We can use law of sines to find BC.

\(\frac{1.5}{\sin 26}=\frac{BC}{\sin 47} \\~\\ \frac{1.5}{\sin 26}*\sin 47 =BC \\~\\ 2.503\text{ km} \approx BC\)

hectictar May 23, 2017
 #2
avatar+129852 
+2

 

Very nice, hectictar.......!!!

 

 

cool cool cool

 May 23, 2017
 #3
avatar+476 
+1

thanks hectictar

 May 30, 2017

0 Online Users