A cylindrical iron bucket without a lid has a base radius of 2 decimeters and a height equal to one time of its diameter. Now paint the inside and outside of the bucket. Find the area to be painted.
一只圆柱无盖铁皮水桶，底面半径2分米，高是直径的1倍，现在把它内外都涂漆，求涂漆的面积是多少．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 2 * 2 * 4</gadget>
<output>50.24</output>

<gadget id="calculator">50.24 * 2</gadget>
<output>100.48</output>

<result>100.48</result>