A triangular street billboard has a base of 12.5 meters and a height of 4 meters. If you want to whitewash this billboard, you need to use 0.8 kilograms of paint per square meter. At least how many kilograms of paint should be prepared?
一块三角形的街头广告牌，底是12.5米，高是4米，如果要粉饰这块广告牌，每平方米要用油漆0.8千克．至少要准备多少千克的油漆？
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">12.5 * 2 * 0.8</gadget>
<output>20</output>

<result>20</result>