The height of a trapezoid is 3 decimeters, the upper base is 4, and the lower base is 6 decimeters. What is the area in square decimeters?
一个梯形的高是3分米，上底4、下底是6分米，面积是多少平方分米．
<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">10 * (3/2)</gadget>
<output>15</output>

<result>15</result>