A rectangle is 5 meters wide, and its length is 4 meters more than its width. What is the area of this rectangle?
一个长方形，宽5米，长比宽多4米，这个长方形的面积是多少？
<gadget id="calculator">5 + 4</gadget>
<output>9</output>

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

<result>45</result>