The area of the rectangle is 18 square meters, the width is 3 meters, and the perimeter is in meters.
长方形的面积是18平方米，宽是3米，周长是多少米．
<gadget id="calculator">18 / 3</gadget>
<output>6</output>

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

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

<result>18</result>