A trapezoidal open space, the upper base is 7.6m, the lower base is 10m, and the height is 4.8m. The largest rectangular concrete floor is laid on this land, and the rest is planted with lawn. What is the area of the lawn?
一块梯形的空地，上底是7.6m，下底是10m，高是4.8m，在这块土地上铺一个最大的长方形水泥地，剩下的种草坪，草坪的面积是多少？
<gadget id="calculator">7.6 + 10</gadget>
<output>17.6</output>

<gadget id="calculator">4.8 / 2</gadget>
<output>2.4</output>

<gadget id="calculator">17.6 * 2.4</gadget>
<output>42.24</output>

<gadget id="calculator">7.6 * 4.8</gadget>
<output>36.48</output>

<gadget id="calculator">42.24 - 36.48</gadget>
<output>5.76</output>

<result>5.76</result>