Question 1082031
If rectangle, y along the building, x for the each adjascent side, A for area;
{{{2x+y=300}}}, and {{{A=xy}}}.


{{{A=x(300-2x)}}}


The two roots for A are  x=0 and  300=2x; 150=x.
The maximum A should be in the exact middle of these two roots:
{{{(0+150)/2=75}}}
or
maximum A is at {{{x=75}}}.


{{{y=300-2x}}}
{{{y=300-2*75}}}
{{{y=150}}}



Side opposite the house, 150 meters;
each side perpendicular to the house 75 meters.