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Triangle sides and perimeter

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by DavoodBeater » Sun Jan 04, 2009 1:24 pm
answer:
the sum of two side must be greater than the 3rd side.
therefore the 3rd side must be smaller than 7, even not equal!
=> None!
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by vivek.kapoor83 » Sun Jan 04, 2009 10:58 pm
Triangle property - sum of any 2 sides > third side
So, 7 > third side

or third side <7
No option is given. SO none

Rem : Perimeter of any figure is the length of sum of all sides.
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by vittalgmat » Mon Jan 05, 2009 1:03 am
Handy way to remember this property of 3rd side:

"DSS" Expanding this we get

Difference of 2 sides < Side < Sum of 2 sides

First letter of each inequality will result in DSS.

HT helps
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by malhotneha » Wed Jan 07, 2009 12:25 pm
Thanks
Last edited by malhotneha on Wed Jan 07, 2009 5:17 pm, edited 1 time in total.
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by sonu_thekool » Wed Jan 07, 2009 12:32 pm
If you plug in 2 for x, you can never draw a triangle.

The rule for the sides of a triangle says that no side is greater or equal to the sum of the two other sides and no side is less than or equal to the difference of the two other sides.

So, x has to be between 3 and 7 ==> 3 < x < 7
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by vittalgmat » Wed Jan 07, 2009 5:05 pm
malhotneha wrote:Bit confused here.

Why can't 9 be the answer:

Perimeter of a triangle is side a+sideb+sidec=2+5+x
Now if x is 2 (its is less than the sum of 2+5)..the perimeter is 9...

what am I doing wrong here???
Pls read my prev comment where I posted the DSS rule.

Hope that helps
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