The sum of the $x$-coordinates of the vertices of a triangle in the Cartesian plane equals $\sqrt{13}$.  Let $S$ equal the sum of the $x$-coordinates of the midpoints of the sides of the triangle. Find $S^2$.
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The sum of the $x$-coordinates of the vertices of a triangle in the Cartesian plane equals $\sqrt{13}$.  Let $S$ equal the sum of the $x$-coordinates of the midpoints of the sides of the triangle. Find $S^2$.
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13
The sum of the $x$-coordinates of the vertices of a triangle in the Cartesian plane equals $\sqrt{13}$.  Let $S$ equal the sum of the $x$-coordinates of the midpoints of the sides of the triangle. Find $S^2$.
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