A parallelogram has three of its vertices at $(-1,0)$, $(2,4)$ and $(2,-4)$.  What is the positive difference between the greatest possible perimeter and the least possible perimeter of the parallelogram?
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A parallelogram has three of its vertices at $(-1,0)$, $(2,4)$ and $(2,-4)$.  What is the positive difference between the greatest possible perimeter and the least possible perimeter of the parallelogram?
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A parallelogram has three of its vertices at $(-1,0)$, $(2,4)$ and $(2,-4)$.  What is the positive difference between the greatest possible perimeter and the least possible perimeter of the parallelogram?
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