There are 4 cylindrical columns with a base diameter of 0.8 meters and a height of 6 meters in the conference hall. Now they need to be painted with 0.5 kilograms of paint per square meter. How many kilograms of paint should be used to paint these columns?
会议大厅里有4根底面直径0.8米，高6米的圆柱形柱子，现在要刷上油漆，每平方米用油漆0.5千克，刷这些柱子要用油漆多少千克？
<gadget id="calculator">3.14 * 0.8 * 6 * 4</gadget>
<output>60.288</output>

<gadget id="calculator">0.5 * 60.288</gadget>
<output>30.144</output>

<result>30.144</result>