Question 123332
He starts with an area of {{{11*14 = 154}}}in2
The area of the bottom is to be {{{80}}} in2
The area of the sides and the removed corners is {{{154 - 80 = 74}}}
If I call the side of the removed square {{{x}}},
then the four sides plus the four removed squares is
{{{4x^2 + 2*(11 - 2x) + 2*(14 - 2x) = 74}}}
{{{4x^2 + 22 - 4x + 28 - 4x = 74}}}
{{{4x^2 - 8x + 50 = 74}}}
{{{4x^2 - 8x - 24 = 0}}}
{{{x^2 - 2x - 6 = 0}}}
solve by completing the square
{{{x^2 - 2x + 1 = 7}}}
{{{(x - 1)^2 = 7}}}
{{{x = 1 + sqrt(7)}}}in answer
or, using calculator,
{{{x = 3.646}}} in