The upper base of the trapezoid is 6 decimeters, the lower base is 8.5 decimeters, and the height is 10 decimeters. What is its area in square decimeters?
梯形的上底是6分米，下底是8.5分米，高是10分米，它的面积是多少平方分米．
<gadget id="calculator">6 + 8.5</gadget>
<output>14.5</output>

<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">14.5 * 5</gadget>
<output>72.5</output>

<result>72.5</result>