The equation \( x+2 y-8=0 \) and \( 2 x+4 y+8=0 \) are representing the two sides of a square. What is the area of the square?

A \( \frac{121}{5} \) sq. unit

B \( \frac{144}{5} \) sq. unit

C \( \frac{81}{5} \) sq. unit