Given that the area of a triangle is 15 square decimeters, what is the area of a rectangle with the same base and height as the triangle?
已知一个三角形的面积是15平方分米，则与这个三角形等底等高的长方形的面积是多少．
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<result>30</result>