A log with a length of 2 meters and a cross-sectional diameter of 40 cm is processed into the largest cuboid wood. If one underside of processed wood is painted, how many square meters is the painted area?
一根长2米的圆木，横截面的直径为40厘米，把它加工成一根最大的长方体木料．如果给加工好的木料的一个底面涂上油漆，涂油漆的面积是多少平方米？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 / 2 / 100 / 2</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(2/5) * (1/10) * 2</gadget>
<output>2/25 = around 0.08</output>

<result>2/25 = around 0.08</result>