The area of a rectangular square is 15 hectares. After expansion, the length is doubled and the width is tripled. What is the area of the square after the expansion?
一个长方形广场的面积是15公顷，扩建后，长扩大到原来的2倍，宽扩大到原来的3倍，扩建后广场的面积是多少公顷？
<gadget id="calculator">15 * 3 * 2</gadget>
<output>90</output>

<result>90</result>