Question 362305
let w = width of entrance.  Then height is w+2.
{{{w(w+2)/2 = 12}}}, or{{{w^2+2w-24=0}}.
By the quadratic formula, the roots are 
{{{(w+6)(w-4) = 0}}} 
w = -6 or w = 4. Drop the negative value.  Therefore the width is 4 feet, the height 6 feet.