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geometery triangle question- only one side given

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Hi

by prasantnaidu » Wed Jun 10, 2009 12:36 am
Hi Sarang,
The standard formula of finding the ht of a equilateral triangle is
(root 3/2) * side.
So (root 3/2)* side=4 root 3(given)
so side = 8

Thus perimeter= 8*3= 24
Hope that make you happy.
if you want some more ways of solving then you can look here :)
https://www.beatthegmat.com/gmat-prep-pr ... 10809.html

Keep Rocking,
Prasant.
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by tohellandback » Wed Jun 10, 2009 1:37 am
or better remember this
property of a 30-60-90 triangle,
sides will be int he ration 1:sqrt(3):2.
side opp angle 30-1
side opp angle 60-sqrt(3)

same way, 45-45-90 triangle has sides in ratio 1:1:sqrt(2)
The powers of two are bloody impolite!!
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by Musiq » Wed Jun 10, 2009 9:27 am
I agree with the posters above that it is very important to know the ratios of sides of standard Right triangles 90/45/45 and 90/60/30.

A good way to know this is being tested is if you see SQRT(2 )or SQRT(3) in the answer choices. That's almost always an indicator that you will need the ratios.
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