The worker divides a cylindrical wood with a height of 1 meter into two parts along the diameter of the bottom surface. At this time, the sum of the surface areas of the two parts increases by 0.8 square meters compared with the original one. Find the original surface area of the wood.
工人把一根高是1米的圆柱形木料，沿底面直径平均分成两部分，这时两部分的表面积之和比原来增加了0.8平方米．求这根木料原来的表面积．
<gadget id="calculator">0.8 / 2 / 1 / 2</gadget>
<output>0.2</output>

<gadget id="calculator">0.2 ** 2</gadget>
<output>0.04</output>

<gadget id="calculator">3.14 * 0.04 * 2</gadget>
<output>0.2512</output>

<gadget id="calculator">3.14 * 0.2 * 2 * 1</gadget>
<output>1.256</output>

<gadget id="calculator">0.2512 + 1.256</gadget>
<output>1.5072</output>

<result>1.5072</result>