The upper base of a trapezoidal billboard is 12 meters, the lower base is 16 meters, and the height is 2 meters. This billboard is painted with a total of 56 kilograms of paint. How much paint is used per square meter on average?
一块梯形广告牌的上底是12米，下底是16米，高是2米，涂这块广告牌一共用油漆56千克，平均每平方米用多少油漆？
<gadget id="calculator">12 + 16</gadget>
<output>28</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">28 * 1</gadget>
<output>28</output>

<gadget id="calculator">56 / 28</gadget>
<output>2</output>

<result>2</result>