SOLUTION: The perimeter and the diagonal of a rectangle are 18m and 5 m respectively. find its area ?

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Question 168667: The perimeter and the diagonal of a rectangle are 18m and 5 m respectively. find its area ?
Found 2 solutions by stanbon, jojo14344:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
The perimeter and the diagonal of a rectangle are 18 and 5 m respectively. find its area ?
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perimeter = 18m
diagonal = 5m ?
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Perimeter = 2(L+W) = 18m
L+W = 9m
L = 9m-W
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Using Pytagoras:
w^2 + (9m-W)^2 = (5m)^2
W^2 + 81m^2 - 18mW + w^2 = 25m^2
56m^2 -18wm +2w^2 = 0
28m^2 - 9wm + 2w^2 = 0
m = [9w +- sqrt(81w^2 -4*28*2w^2)]/56
m = [9w +- sqrt(-143w^2)]/56
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Comment: Since you have a negative radicand you have no Real Number solution.
=====================================
Cheers,
Stan H.




Cheers,
Stan H.

Answer by jojo14344(1513)   (Show Source): You can put this solution on YOUR website!
That forms 2 Right Triangles with the diagonal right?
See below,

In a Pyth. theorem, a Right Triangle with (diagonal), has other sides measure: and
Proof: Pyth.Theorem:


, good
.
Therefore,

Since it forms 2 triangles:

*Note:

.
, ANSWER
.
*Now, this is misleading data, having . It doesn't make sense. If we calculate , Does not match up. PLEASE VERIFY THIS.
Thank you,
Jojo

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