If there are two identical rectangles with a length of 8 cm and a width of 4 cm, put them together to form a square. What is the perimeter of the square in cm?
有两个一样的长方形，长都是8厘米，宽都是4厘米，把它们拼成一个正方形，这个正方形的周长是多少厘米．
<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<result>32</result>