The area of the trapezoid is 16.5 square decimeters and the height is 3 decimeters. The upper bottom is 8 decimeters, and the lower bottom is how many decimeters.
梯形的面积是16.5平方分米，高是3分米．上底是8分米，下底是多少分米．
<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">8 * (3/2)</gadget>
<output>12</output>

<gadget id="calculator">16.5 - 12</gadget>
<output>4.5</output>

<gadget id="calculator">4.5 / (3/2)</gadget>
<output>3</output>

<result>3</result>