The length of a rectangle is 16 decimeters and the width is 6 decimeters. If the length is increased by 15 decimeters, how many decimeters will the perimeter become?
长方形的长16分米，宽6分米，如果长增加15分米，周长变成多少分米？
<gadget id="calculator">31 + 6</gadget>
<output>37</output>

<gadget id="calculator">37 * 2</gadget>
<output>74</output>

<result>74</result>