The lower base of the trapezoid is 8 decimeters, the upper base is half of the lower base, and the height is 1 meter. Find the area of the trapezoid.
梯形的下底是8分米，上底是下底的一半，高是1米，求梯形的面积．
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">8 + 4</gadget>
<output>12</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">12 * (1/2)</gadget>
<output>6</output>

<result>6</result>