(x-y)^2-2x+2y+1=0
(x-y)²-2(x-y)+1=0
(x-y-1)²=0
x-y-1=0
x-y=1
由题可知x+y=14÷2=7
则x=(7+1)÷2=4cm
y=(7-1)÷2=3cm
S=xy=3×4=12cm²