The area of a rectangle is 18 square meters. If its length is tripled and its width remains the same, what is the area?
一个长方形面积是18平方米，若将它的长扩大3倍，宽不变，面积是多少．
<gadget id="calculator">18 * 3</gadget>
<output>54</output>

<result>54</result>