<em>Here</em> as the <em>Pentagon</em> is <em>regular</em> so it's <em>all sides</em> will be of <em>equal length</em> . And if we assume It's each side be<em> </em><em><u>s</u></em> , then it's perimeter is going to be <em>(s+s+s+s+s) = </em><em><u>5s</u></em>.And as here , each <em>side</em> is increased by <em>8 inches</em> and then it's perimeter is <em>65 inches</em> , so we got that it's side after increament is<em> (s+8) inches</em> and original length is <em>s inches </em>. And if it's each side is <em>(s+8) inches</em> , so it's perimeter will be <em>5(s+8)</em> and as it's equal to <em>65 inches</em> . So , <em><u>5(s+8) = 65</u></em>
As we assumed the original side to be <em><u>s</u></em> .
<em>Hence, the original side's length 5 inches </em>