The length of a rectangle is 16 decimeters and the width is 6 decimeters. If the length increases by 15 decimeters, how much does the perimeter increase?
长方形的长16分米，宽6分米，如果长增加15分米，周长增加多少分米？
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<result>30</result>