A triangle-shaped traffic signboard has a base of 1.3 meters and a height of 0.9 meters. If one side of the signboard is painted with paint, 0.8 kilograms of paint is used per square meter. How many kilograms of paint should be used at least?
一个形状是三角形的交通标志牌，底是1.3米，高是0.9米，如果用油漆刷这块标志牌的一面，每平方米用油漆0.8千克，至少要用油漆多少千克？
<gadget id="calculator">0.9 / 2</gadget>
<output>0.45</output>

<gadget id="calculator">1.3 * 0.45 * 0.8</gadget>
<output>0.468</output>

<result>0.468</result>