If the base of a parallelogram is 6 cm and the height is 3.5 cm, what is the area of the parallelogram in square centimeters?
一个平行四边形的底是6厘米、高是3.5厘米，这个平行四边形的面积是多少平方厘米．
<gadget id="calculator">6 * 3.5</gadget>
<output>21</output>

<result>21</result>