The upper base of a trapezoid is 8 cm, the lower base is 15 cm, and the height is 6 cm. What is the area in square centimeters?
一个梯形的上底是8厘米，下底是15厘米，高是6厘米，面积是多少平方厘米．
<gadget id="calculator">8 + 15</gadget>
<output>23</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">23 * 3</gadget>
<output>69</output>

<result>69</result>