Cut a square with a side length of 6 decimeters into two identical rectangles, what is the perimeter of one of the rectangles in decimeters?
把边长6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">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 + 6</gadget>
<output>9</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>