Question 704981
Rectangle.  Perimeter=200 ft.  Area=1275 ft^2.
x, y, length, width.

System:
2(x+y)=200
xy=1275


x+y=100, divided perim. equation by 2.
y=100-x
substitute to get x(100-x)=1275
100x-x^2-1275=0


Solution to quadratic equation:
{{{x=(1+(1-4*100*(-1275))^(1/2))/(2*100)}}}
OR
{{{x=(1-(1-4*100*(-1275))^(1/2))/(2*100)}}}


One of those will work and one will not.