The base of a parallelogram is 15 cm, and the height is twice the base. What is the area of the parallelogram in square centimeters?
一个平行四边形形的底是15厘米，高是底的2倍，平行四边形的面积是多少平方厘米？
<gadget id="calculator">15 * 2 * 15</gadget>
<output>450</output>

<result>450</result>