The area of a rectangular lawn is 840 square meters. It is known that its length is 35 meters. If a fence is to be built around the lawn, how long is the fence?
一个长方形草坪的面积是840平方米．已知它的长是35米，要在草坪四周围上篱笆，篱笆长多少米？
<gadget id="calculator">840 / 35</gadget>
<output>24</output>

<gadget id="calculator">35 + 24</gadget>
<output>59</output>

<gadget id="calculator">59 * 2</gadget>
<output>118</output>

<result>118</result>