A pile of logs is piled up in a trapezoidal shape. There are 3 logs in the top layer, 8 logs in the bottom layer, and 6 layers in height. How many logs are there in total in this pile?
一堆圆木堆成梯形，最上层有3根，最下层有8根，高6层，这堆圆木一共有多少根？
<gadget id="calculator">3 + 8</gadget>
<output>11</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">11 * 3</gadget>
<output>33</output>

<result>33</result>