The area of a trapezoid is 48 square meters, the height is 8 meters, and the upper base is 4 meters. What is the lower base in meters?
一个梯形的面积是48平方米，高是8米，上底是4米，它的下底是多少米．
<gadget id="calculator">2 / 8</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">48 * (1/4)</gadget>
<output>12</output>

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

<result>8</result>