A rectangle with a perimeter of 42 cm has a length of 14 cm, what is its area in square centimeters?
一个周长42厘米的长方形，它的长是14厘米，它的面积是多少平方厘米？
<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<gadget id="calculator">21 - 14</gadget>
<output>7</output>

<gadget id="calculator">14 * 7</gadget>
<output>98</output>

<result>98</result>