Paint a cylindrical tin ventilation pipe. The length of the pipe is 1.8m, and the diameter of the nozzle is 1dm. If 0.2kg of paint is used per square meter, how many kilograms of paint should be used at least?
油漆一个圆柱形铁皮通风管．管长1.8m，管口直径1dm，如果每平方米用油漆0.2千克，至少要用油漆多少千克？
<gadget id="calculator">3.14 * 1 * 1.8</gadget>
<output>5.652</output>

<gadget id="calculator">0.2 * 5.652</gadget>
<output>1.1304</output>

<result>1.1304</result>