Question 1136797
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<pre>
Notice that the old patio is a square.


New patio is a square, too.


The new patio side length is  {{{sqrt(180)}}} = 13.42 feet.


The border width = {{{(13.42-12)/2}}} = 0.7 feet (rounded as requested).    <U>ANSWER</U>
</pre>

Solved.


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To solve this problem, you do not need to setup and to solve a quadratic equation.