A triangular billboard has a base of 1.6 meters and a height of 1.5 meters. If you want to paint the billboard on both sides, you need to use 0.7 kilograms of paint per square meter. How many kilograms of paint should you prepare at least?
一个三角形的广告牌，底是1.6米，高是1.5米，如果要两面油漆装饰这块广告牌，每平方米用油漆0.7千克，至少要准备多少千克的油漆？
<gadget id="calculator">1.5 / 2</gadget>
<output>0.75</output>

<gadget id="calculator">1.6 * 0.75 * 2</gadget>
<output>2.4</output>

<gadget id="calculator">2.4 * 0.7</gadget>
<output>1.68</output>

<result>1.68</result>