The upper base of a trapezoid is 9 cm, the lower base is 0.2 times the upper base, and the height is 3 cm. What is its area in square centimeters?
一个梯形的上底是9厘米，下底是上底的0.2倍，高是3厘米，它的面积是多少平方厘米．
<gadget id="calculator">9 * 0.2</gadget>
<output>1.8</output>

<gadget id="calculator">9 + 1.8</gadget>
<output>10.8</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">10.8 * (3/2)</gadget>
<output>16.2</output>

<result>16.2</result>