The length of a rectangle is 4 cm and the width is half the length. What is the area of the rectangle?
一个长方形的长为4厘米，宽是长的一半，这个长方形的面积是多少．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<result>8</result>