rectangle is formed with a 30-meter-long rope (the sides are rounded to whole meters), what is the maximum area of the rectangle in square meters?
用30米长的绳子围成一个长方形(边取整米数)，则长方形的面积最大是多少平方米．
<gadget id="calculator">8 * 7</gadget>
<output>56</output>

<result>56</result>