A triangular vegetable plot is drawn on the drawing at a scale of 1:400. The measured base length is 10 cm and the height above the base is 8 cm. What is the actual area of the vegetable plot in square meters?
一块三角形菜地按1：400的比例尺画在图纸上，量得底长10厘米，底边上的高为8厘米，则这块菜地的实际面积是多少平方米？
<gadget id="calculator">1 / 400</gadget>
<output>1/400 = around 0.0025</output>

<gadget id="calculator">10 / (1/400) / 100</gadget>
<output>40</output>

<gadget id="calculator">8 / (1/400) / 100 / 2</gadget>
<output>16</output>

<gadget id="calculator">40 * 16</gadget>
<output>640</output>

<result>640</result>