The perimeter of a rectangle is 36dm, the length is 10dm, what is the area in square decimeters?
一个长方形周长是36dm，长是10dm，面积是多少平方分米？
<gadget id="calculator">36 / 2</gadget>
<output>18</output>

<gadget id="calculator">18 - 10</gadget>
<output>8</output>

<gadget id="calculator">10 * 8</gadget>
<output>80</output>

<result>80</result>