Question 403206
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Since the diagonals are congruent, the parallelogram must be a rectangle.  That means either of the diagonals is the hypotenuse of a right triangle with adjacent sides of the rectangle as legs.  Recognize that 5-12-13 is a Pythagorean Triple, hence the remaining leg must measure 12.  Or use the Pythagorean Theorem and solve:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ b\ =\ \sqrt{13^2\ -\ 5^2}]


for *[tex \Large b] giving you the other dimension of the rectangle.


Finally, use the formula for the perimeter of a rectangle to calculate the perimeter:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ P\ =\ 2l\ +\ 2w]


John
*[tex \LARGE e^{i\pi} + 1 = 0]
My calculator said it, I believe it, that settles it
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