What is the perimeter of a rectangle whose length is 4 decimeters and width is 3 decimeters?
长是4分米，宽是3分米的长方形，周长多少分米．
<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<result>14</result>