Question 327568
If it's a square, then the sides should both equal {{{z+6}}}.
If it has sides that have different lengths, it's a rectangle.
The perimeter of a rectangle is,
{{{P=2*L+2*W=2(z+6)+2(z)=4z+6}}}
The area of a rectangle is,
{{{A=L*W=(z+6)z=z^2+6z}}}