Question 1095760
<br>Re-stated: (x+7) squared is 189 more than x squared.  So
{{{(x+7)^2 = x^2 + 189}}}
{{{x^2+14x+49 = x^2+189}}}
{{{14x = 140}}}
{{{x = 10}}}<br>
The original square had side length 10.