Hi,
(x+5)^2 + (x-2)^2 = (x+6)^2
x^2 + 10x + 25 + x^2 - 4x + 4 = x^2 + 12x + 36
x^2 -6x -7 = 0
factoring
(x+1)(x-7)=0
(x+1)=0
x = -1 Tossing out negative solution
(x-7)=0
x = 7m (length = 12m and width = 5m)
Area is: 12m*5m = 60m^2
Perimeter is: 2*12m + 2*5m = 34m