Build a cylindrical biogas digester with a bottom circumference of 18.84 meters and a depth of 2 meters. Put cement on the four walls and bottom of the pool, how many square meters is the area of the cement part?
修建一个圆柱形的沼气池，底面周长是18.84米，深2米．在池的四壁与下底面抹上水泥，抹水泥部分的面积是多少平方米？
<gadget id="calculator">18.84 * 2</gadget>
<output>37.68</output>

<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<gadget id="calculator">37.68 + 28.26</gadget>
<output>65.94</output>

<result>65.94</result>