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I'm stuck on this and don't know where to start. How do you do this step by step?

 Nov 12, 2019
 #1
avatar+19794 
+1

Well, obviously, she shoud aim at point E.....   haha   jk

Distance D = (12+9+9)  -  27  = 3

   The two angles at E are equal    (angle of incidence = angle of reflection, generally) 

       the large and the smaller triangle are similar triangles.....

           Does all of that give ya a clue?   cheeky

 Nov 12, 2019
edited by ElectricPavlov  Nov 12, 2019
 #2
avatar+49 
+1

Ummm... I'm not quite sure. What I'm supposed to do from there? Maybe explain how to get where to aim at the wall?

GAMEMASTERX40  Nov 13, 2019
 #3
avatar+19794 
+1

Similar triangles....

3 is to 12   as   CE is to EB       AND    CE+ EB =20

 

3/12 = CE/EB   

1/4  = CE/ EB              Want me to finish it or can you try from here?  Do you remember how to solve ratios?

 Nov 13, 2019
edited by ElectricPavlov  Nov 13, 2019
 #4
avatar+49 
+1

Yeah, can you finish it from there? This is supposed to be the last question on my work. I do know about the ratios but similar tringles always get me. Thanks!

 Nov 13, 2019
 #5
avatar+19794 
+1

I have reduced the similar triangles it to a simple ratio problem....you should be able to solve it:

1/4 = CE/EB      and   CE + EB = 20

 

so out of FIVE parts   (1+4)    CE is ONE of them  and EB is FOUR of them

20 divided by 5 parts = 4 per part

   so CE = 4    EB = 16         CE/EB = 4/16 = 1/4       DO you see how to do ratios nw?

ElectricPavlov  Nov 13, 2019
 #6
avatar+105476 
+2

Note that angles EBA  and ECD   are  equal  right angles

And angle BEA  = angle CED

 

So triangle  EBA  is similar to triangle ECD

 

So

 

BE / BA  = CE / DC

 

BA  = 12

Let EB =   20 - x

Let CE  = x

DC  = (12 + 9 + 9)  - 27  = 3

 

So  we have that

 

[20 - x] / 12 =  x / 3              cross-multiply

 

3[20 - x]  =  12x              simplify

 

60 - 3x  = 12x                rearrange as

 

60 = 15x       divide both sides by  15

 

x = 4

 

She should aim 4 ft to the right of  "C"

 

EDIT TO CORRECT A PREVIOUS MISTAKE.....THANKS TO EP FOR CATCHING THIS    !!!!

 

 

cool cool cool

 Nov 13, 2019
edited by CPhill  Nov 13, 2019
 #7
avatar+49 
+1

Thank you very much CPhill this is just what I needed to complete my work. Very understandable too and I saw your helpful correction to figure out the answer to the problem.

GAMEMASTERX40  Nov 14, 2019

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