A rectangle has a perimeter of 240 cm and a length of 70 cm, what is its area?
一个长方形的周长是240厘米，长70厘米，求它的面积？
<gadget id="calculator">240 / 2</gadget>
<output>120</output>

<gadget id="calculator">120 - 70</gadget>
<output>50</output>

<gadget id="calculator">70 * 50</gadget>
<output>3_500</output>

<result>3_500</result>