Answer: 11
Through trial and error, you should find that 11*11 = 121
A more methodical approach is to let x be the length and width, so x*x = x^2 is the area. Set this equal to 121 and solve for x. Use the square root to undo the square
x^2 = 121
sqrt( x^2 ) = sqrt( 121 )
x = 11
