A trapezoidal nursery, the upper base is 4m long, the lower base is 6m long, and the height is 5m. What is its area in square meters?
一个梯形苗圃，上底长4m，下底长6m，高5m，它的面积是多少平方米．
<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">10 * (5/2)</gadget>
<output>25</output>

<result>25</result>