A triangle and a parallelogram with the same base and height, the known area of the triangle is 7.5 square centimeters, what is the area of the parallelogram in square centimeters.
一个等底等高的三角形与平行四边形，已知三角形的面积是7.5平方厘米，平行四边形的面积是多少平方厘米．
<gadget id="calculator">7.5 * 2</gadget>
<output>15</output>

<result>15</result>