If the perimeter of a rectangle is 24 cm and the length is 8 cm, what is its area in square centimeters?
一个长方形的周长是24厘米，长是8厘米，它的面积是多少平方厘米．
<gadget id="calculator">24 / 2</gadget>
<output>12</output>

<gadget id="calculator">12 - 8</gadget>
<output>4</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<result>32</result>