187 cm squared.
Based on rectangle:
2L + 2W = 56
Draw the square and name your sides the following:
(W+4) , (L-2), (W+4), (L-2)
Because it’s a square, all sides are equal and we can remove and solve for one of the variables but keep in mind the parameter changed..
The new parameter is 56 minus 4cm + 8cm...keep in mind I used 4cm and 8cm because we have a 2 Lengths and 2 Widths.
Solving 60= 4 (w+4)
W= 11
So the side of our square is 11+4=15
L-2 = 15
L=17
So the area of the Rectangle is 11*17=187 cm squared.
Please let me know if it’s correct !