<PRE><B>Question 785624</B>
A = x(4x)

144 = 4x^2

144/4 = x^2

36 = x^2

Taking the square root of both sides yields 
x = 6. 

P = 2x + 2(4x)

Let x be 6 and solve for P to find your perimeter.

I hope this helps. </PRE>