You can't deduce the length of a side from the perimeters of a rectangle.
Say that [tex]s[/tex] and [tex]S[/tex] are, respectively, the short and long side of the rectangle.
So, we know that
[tex]2s+2S=130 \iff 2(s+S)=130 \iff s+S=65[/tex]
But we can't solve exactly for [tex]s[/tex] nor for [tex]S[/tex], unless more information is given.
