Build a cylindrical biogas tank with a bottom diameter of 4 meters and a depth of 3 meters. Put cement on the four walls and bottom of the tank. What is the area of the cemented part? (π takes 3)
修建一个圆柱形沼气池，底面直径是4米，深3米，在池的四壁及下底抹上水泥，那么抹水泥部分的面积多少㎡．(π取3)
<gadget id="calculator">3 * 4 * 3</gadget>
<output>36</output>

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

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

<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<gadget id="calculator">36 + 12</gadget>
<output>48</output>

<result>48</result>