Uncle Li surrounded a trapezoidal vegetable field with a fence. The top, bottom and height are (7/8) meters, 2.5 meters and 8 meters respectively. How many square meters is the area of this vegetable field?
李叔叔用篱笆围了一块梯形菜地，上底、下底和高分别是(7/8)米，2.5米和8米，这块菜地的面积是多少平方米？
<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">(7/8) + 2.5</gadget>
<output>3.375</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">3.375 * 4</gadget>
<output>13.5</output>

<result>13.5</result>