The perimeter of a rectangle is 20 decimeters, the width is 20 centimeters, what is the length in centimeters
一个长方形的周长是20分米，宽是20厘米，长是多少厘米
<gadget id="calculator">20 * 10</gadget>
<output>200</output>

<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<gadget id="calculator">100 - 20</gadget>
<output>80</output>

<result>80</result>