A rectangle with an area of 300 square centimeters has a length of 20 centimeters and a width of 20 centimeters.
一个面积是300平方厘米的长方形，长是20厘米，宽是多少厘米．
<gadget id="calculator">300 / 20</gadget>
<output>15</output>

<result>15</result>