The height of a cylindrical oil drum is 10 decimeters, and its side is expanded to form a rectangle with a length of 25.12 decimeters. What is the surface area of the barrel in square feet?
一个圆柱形油桶的高是10分米，它的侧面展开得到一个长方形，长是25.12分米．这个油桶的表面积是多少平方分米．
<gadget id="calculator">25.12 * 10</gadget>
<output>251.2</output>

<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16 * 2</gadget>
<output>100.48</output>

<gadget id="calculator">251.2 + 100.48</gadget>
<output>351.68</output>

<result>351.68</result>