A trapezoid, the upper base is 8 cm, the lower base is (3/2) times the upper base, and the height is (1/2) shorter than the upper base, what is the area of the trapezoid?
一个梯形，上底是8厘米，下底是上底的(3/2)倍，高比上底短(1/2)，梯形的面积是多少．
<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">8 + 12</gadget>
<output>20</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) / 2</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">20 * 8 * (1/4)</gadget>
<output>40</output>

<result>40</result>