There is a rectangle and a square with the same perimeter. The length of the rectangle is 12 cm and the width is 8 cm. What is the side length of the square in cm?
有一个长方形和正方形，它们的周长相等，长方形的长是12厘米，宽是8厘米，正方形的边长是多少厘米？
<gadget id="calculator">12 + 8</gadget>
<output>20</output>

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

<gadget id="calculator">20 * (1/2)</gadget>
<output>10</output>

<result>10</result>