A quadrilateral is formed by 100 cm long wire, what is the maximum area of the quadrilateral in square centimetres?
用100厘米长的铁丝围成四边形，这个四边形的面积最大是多少平方厘米．
<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">25 * 25</gadget>
<output>625</output>

<result>625</result>