A rectangle and a parallelogram have the same area. The length of the rectangle is 20 decimeters, the width is 18 decimeters, the base of the parallelogram is 12 decimeters, how many decimeters is the height of the parallelogram?
一个长方形和一个平行四边形的面积相等．长方形长20分米，宽18分米，平行四边形的底是12分米，平行四边形的高是多少分米？
<gadget id="calculator">18 / 12</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">20 * (3/2)</gadget>
<output>30</output>

<result>30</result>