# Is it a triangle?

Geometry Level 3

Let $$x, y$$ be positive integers such that a triangle with the side lengths of $$\sqrt{25x^2+16y^2} , 2\sqrt{4x^2+y^2}, \sqrt{81x^2+4y^2}$$ has area $$39$$.

Find the total possible numbers of ordered pairs $$(x, y)$$.

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