A rectangle and a square have the same perimeter. The length of the rectangle is 8 meters and the width is 5 meters. What is the side length of the square?
一个长方形和一个正方形的周长相等，长方形的长是8米，宽是5米，正方形的边长是多少米？
<gadget id="calculator">8 + 5</gadget>
<output>13</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">13 * (1/2)</gadget>
<output>13/2 = around 6.5</output>

<result>13/2 = around 6.5</result>