The perimeter of a rectangle is 28 cm and the length is 9 cm. What is the area of the rectangle in square centimeters?
一个长方形的周长是28厘米，长是9厘米，这个长方形的面积是多少平方厘米．
<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">14 - 9</gadget>
<output>5</output>

<gadget id="calculator">9 * 5</gadget>
<output>45</output>

<result>45</result>