What is the area of a parallelogram with a base of 9 cm and a height of 2 decimeters?
平行四边形的底9厘米，高2分米，它的面积是多少平方厘米．
<gadget id="calculator">2 * 10</gadget>
<output>20</output>

<gadget id="calculator">9 * 20</gadget>
<output>180</output>

<result>180</result>