There is a triangular test field, the bottom is 50 meters, and the height is 10 meters less than the bottom. If 20 kilograms of corn are harvested per square meter, how many kilograms of corn can be harvested in this test field?
有一块三角形试验田，底是50米，高比底少10米，如果每平方米收玉米20千克，这块试验田可以收玉米多少千克？
<gadget id="calculator">50 - 10</gadget>
<output>40</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">50 * 20 * 20</gadget>
<output>20_000</output>

<result>20_000</result>