Count the total number of squares = 9

Now given that total area of the figure = 576 cm^{2}

and each square is of same area

so, area of one square = 576/9 = 64 cm^{2}

so, each side of square = **√**64 = 8 cm

We know that perimeter of the figure is the sum of the outer side of the square = 20*8 = 160 cm