Question 878859
x = side length of the square region including where the building.


Parking Lot plus Building Lot = {{{x^2}}} square feet.
{{{21100+70*20=x^2}}}
{{{x^2=21100+1400}}}
{{{x^2=22500}}}
{{{x^2=100*9*25}}}
{{{x=10*3*5}}}
{{{highlight(x=150)}}}, side length of the entire land plot.