A triangle and a parallelogram have the same base and height, and the area of the triangle is 10 square centimeters, what is the area of the parallelogram?
一个三角形和一个平行四边形等底等高，三角形的面积是10平方厘米，那么平行四边形的面积是多少．
<gadget id="calculator">10 * 2</gadget>
<output>20</output>

<result>20</result>