The upper base of a trapezoid is 7.5 cm, the lower base is 10.5 cm, and the height is 9.6 cm. What is its area in cm**2.
一个梯形上底是7.5cm，下底是10.5cm，高是9.6cm，它的面积是多少cm**2．
<gadget id="calculator">7.5 + 10.5</gadget>
<output>18</output>

<gadget id="calculator">9.6 / 2</gadget>
<output>4.8</output>

<gadget id="calculator">18 * 4.8</gadget>
<output>86.4</output>

<result>86.4</result>