A 240-meter-long fence and a wall form a rectangle together. What is the maximum area in square meters?
用长240米的篱笆和一面墙，一起围成一个长方形，面积最大是多少平方米．
<gadget id="calculator">1 + 2 + 1</gadget>
<output>4</output>

<gadget id="calculator">240 / 4</gadget>
<output>60</output>

<gadget id="calculator">60 * 1</gadget>
<output>60</output>

<gadget id="calculator">60 * 2</gadget>
<output>120</output>

<gadget id="calculator">240 - 120</gadget>
<output>120</output>

<gadget id="calculator">120 * 60</gadget>
<output>7_200</output>

<result>7_200</result>