A square has an area of 4x^2+12xy+9y^2 square meters. What is the perimeter of the square?

1. (a ± b)^{2} = a^{2} ± 2ab + b^{2}

2. A = a^{2} , P = 4a

A = (2x)^{2} + 2 · 2x · 3y + (3y)^{2} = (2x + 3y)^{2}

P = 4(2x + 3y) = **8x + 12y**