The upper base of a trapezoid is 8 cm, the lower base is 10 cm, and the height is 2 cm. What is the area in square centimeters?
一个梯形的上底是8厘米，下底是10厘米，高是2厘米，面积是多少平方厘米．
<gadget id="calculator">8 + 10</gadget>
<output>18</output>

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

<gadget id="calculator">18 * 1</gadget>
<output>18</output>

<result>18</result>