The area of a triangle is 3 square decimeters, the height remains the same, and the base is enlarged to 3 times its original size, what is the area of the triangle in square decimeters
一个三角形的面积是3平方分米，高不变，底扩大到原来的3倍，三角形的面积是多少平方分米
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<result>9</result>