There is a trapezoidal vegetable field whose height is 20m, and its two parallel sides are 30m and 15m respectively. If sweet potatoes are planted on this vegetable field, if the average yield of sweet potatoes per square meter is 16.5 kg, how many kilograms of sweet potatoes can be harvested in this vegetable field?
有一块梯形菜地的高是20m，它的两条平行的边分别是30m和15m．在这块菜地上种白薯，如果平均每平方米收白薯16.5千克，这块菜地可以收多少千克白薯？
<gadget id="calculator">15 + 30</gadget>
<output>45</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">45 * 10 * 16.5</gadget>
<output>7_425</output>

<result>7_425</result>