Aadarsh
Area of a regular octagon is 4(root 2 + 1) square units. Find its side.
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Aadarsh
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|dw:1334302795177:dw|
Aadarsh
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@Taufique bhai, please help.
Aadarsh
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Let the side of octagon be "x" units.
fractal5
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\[4\sqrt{2+1}\]
or
\[4\sqrt{2}+1\]
Aadarsh
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|dw:1334303032758:dw|
@fractal5 , the first one
fractal5
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are you sure, because that is = \[4\sqrt{3}\]
Aadarsh
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Now, |dw:1334303202974:dw|
Aadarsh
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The actual area is :|dw:1334303237350:dw|
fractal5
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Area = ( 2 + 2√2 )*(x^2)
where x is the side length
Taufique
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in the regular octagon.there will be 8 equilateral triangle hence let the side is x.
then area of octagon=8*area of one equilateral triangle
=\[8\times \sqrt{3}\div 4 (x ^{2})\]..find x.
Aadarsh
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@Taufique bhai, can u say the answer?
fractal5
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Are you sure they are equilateral? I think in a hexagon they are equil. not octagon
Aadarsh
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Even I am in doubt whther we will get 8 equilateral traingles or not.
fractal5
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Just solve the formula I gave
Aadarsh
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@fractal5 , u r rite. I got it. Can u say how u got it?
Aadarsh
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@fractal5,can u plz explain the formula how u got it?
Aadarsh
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@gurvinder bhai, can u explain the formula?
Taufique
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@Aadarsh fractal is right ..
|dw:1334303786166:dw|
Aadarsh
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Okay. But can u explain the formula which @fractal5 used? plzzzzzzzz
Aadarsh
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@Taufique bhai, u der?
Taufique
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|dw:1334304124446:dw|
find its area and multiply it by 8 and put it equal to given area in your question...
Aadarsh
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But, now can u explain the nest step? The height and side in terms of "x"?
Taufique
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Aadarsh wait.
Aadarsh
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Okay bhai. I will be coming in 15 minutes after lunch.
Taufique
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|dw:1334304950665:dw|
put the value of tan67.5 deg equal to
Aadarsh
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Okay bhai. But how to obtain value of tan 67.5?
Taufique
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tan67.5deg=root2+1 put there and find x
Taufique
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|dw:1334305364185:dw|
Taufique
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@Aadarsh ab kho bhai koi problem.. sorry kam kar rha tha college ka project tha.
Taufique
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Aadarsh khan ho.
Taufique
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|dw:1334305876442:dw|
find tan67.5 from here.
Aadarsh
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But abhi isko solve kaise karenge?
Taufique
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tan67.5=x let
|dw:1334306229613:dw|
x=root2+1 is only possible because 67.5 is in first quadrant and in first quadrant tan ins positive.hence neglect negative value(1-root2)
Aadarsh
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OH yeah I got it. Thanks bhai!!!!!!!
Taufique
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ji han vai apko v dhanyabad samajne k liye..
Aadarsh
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Thanks ji.