Cut a square with a side length of 4 decimeters into two identical rectangles, what is the perimeter of one of the rectangles in decimeters?
把边长4分米的正方形剪成两个同样的长方形，其中一个长方形的周长是多少分米．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 + 4</gadget>
<output>6</output>

<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<result>12</result>