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Math Help - A rectangle with a diagonal of length is twice as long as it is wide. What is the ar

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    A rectangle with a diagonal of length is twice as long as it is wide. What is the ar

    A rectangle with a diagonal of length is twice as long as it is wide. What is the area of the rectangle in terms of ?
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    Quote Originally Posted by sri340 View Post
    A rectangle with a diagonal of length is twice as long as it is wide. What is the area of the rectangle in terms of ?
    Let a denote the width, then 2a denote the length.

    Calculate the length of the diagonal using Pythagorean theorem:

    x^2 = (2a)^2+a^2~\implies~x^2 = 5a^2

    The area of the rectangle is:

    A = 2a \cdot a = 2a^2

    Transform the first equation such that the RHS equals 2a^2

    x^2 = 5a^2~\implies~\dfrac25 x^2 = 2a^2 = A
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