A rectangular playground is 250 meters long and 180 meters wide. What is the perimeter of the playground?
一个长方形运动场，长250米，宽180米，这个运动场的周长是多少米？
<gadget id="calculator">250 + 180</gadget>
<output>430</output>

<gadget id="calculator">430 * 2</gadget>
<output>860</output>

<result>860</result>