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# my qestion

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camili is 5 feet tall. she placed a mirror on the ground 6 feet from a lamppost. she moved back 3 feet to see the top of the post what is the hieght of the lamppost

Guest Nov 13, 2015
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#1
+82721
+5

I believe this has something to do with the angle of incidence and reflection.

The angle of elevation formed by her line of sight and her distance from the mirror  is given by :

atan [5 / 3]   = about 59.04°

And this would be the same angle of elevation formed by the distance the mirror is from the top of the post  and its distance to the post....so we have......

tan (59.04)  = h / 6      where h is the post height

[5/3]  = h / 6     cross-multipy

5 * 6 / 3 = h     =  30/ 3  = 10 ft tall

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I'd like to have someone else look at this one......I might be out in left field, here....!!!!!

CPhill  Nov 13, 2015
edited by CPhill  Nov 13, 2015
edited by CPhill  Nov 13, 2015
#2
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I would have done the same thing Chris but I am not completely certain either.

Melody  Nov 13, 2015

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