A rectangle has a perimeter of 240 meters and its length is 1.4 times its width. Find the area of a rectangle (use equations and column methods to solve problems)
一个长方形的周长是240米，长是宽的1.4倍．求长方形的面积(使用方程和列式方法解题)
<gadget id="calculator">1 + 1.4</gadget>
<output>2.4</output>

<gadget id="calculator">240 / 2 / 2.4</gadget>
<output>50</output>

<gadget id="calculator">50 * 1.4 * 50</gadget>
<output>3_500</output>

<result>3_500</result>