A rectangle is surrounded by 24 matchsticks with a length of l cm. What is the maximum area of this rectangle? What if 22 matchsticks are used?
用24根长l厘米的火柴棒围成一个矩形，这个矩形的面积最大是多少？如果用22根火柴棒呢？
<gadget id="calculator">5 * 6</gadget>
<output>30</output>

<result>30</result>