A rectangular test field is 20 meters wide and 4 times as long as it is wide. What is the perimeter of this rectangle in meters?
一块长方形试验田，宽20米，长是宽的4倍．这个长方形的周长是多少米？
<gadget id="calculator">20 * 4</gadget>
<output>80</output>

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

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

<result>200</result>