What is the area of a triangular test field with a base length of 40 meters and a height twice that of the base?
一块三角形试验田，底长40米，高是底的2倍，它的面积是多少？
<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">40 * 40 * 1</gadget>
<output>1_600</output>

<result>1_600</result>