Question 683823
In a square all sides, s, are the same, so instead of a=lw, we can substitute
a = s^2.
...
169 = s^2
Take the square root of each side
{{{sqrt(s^2)}}} = +/-{{{sqrt(169)}}}
s = +/- 13
However, a side cannot have a negative dimension, so
{{{highlight_green(s = 13)}}}
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