A cylindrical biogas digester was built in the school cafeteria, with a bottom diameter of 4 meters and a depth of 3 meters. The four walls and the lower bottom of the pond are plastered with cement. How many square meters is the cement plastered?
学校食堂修建了一个圆柱形沼气池，底面直径是4米，深3米，在池的四壁和下底面抹上水泥，抹水泥的面积是多少平方米？
<gadget id="calculator">3.14 * 4 * 3</gadget>
<output>37.68</output>

<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<gadget id="calculator">37.68 + 12.56</gadget>
<output>50.24</output>

<result>50.24</result>