A trapezoidal board, the upper base is 16 cm long, the lower base is 1.4 times as long as the upper base, and the height is 15 cm. What is the area of this board?
一个梯形木板，上底长16厘米，下底长是上底的1.4倍，高是15厘米，这块木板的面积是多少？
<gadget id="calculator">16 * 1.4</gadget>
<output>22.4</output>

<gadget id="calculator">16 + 22.4</gadget>
<output>38.4</output>

<gadget id="calculator">15 / 2</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">38.4 * (15/2)</gadget>
<output>288</output>

<result>288</result>