Two identical trapezoids are put together to form a parallelogram. The base of the parallelogram is 8.5 cm and the height is 6 cm. What is the area of each trapezoid in square centimeters?
两个完全一样的梯形拼成一个平行四边形，平行四边形的底是8.5厘米，高是6厘米，每个梯形的面积是多少平方厘米．
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">8.5 * 3</gadget>
<output>25.5</output>

<result>25.5</result>