The inner wall and the bottom of a cylindrical pool should be plastered with cement. The diameter of the bottom of the pool is 4 meters, and the depth of the pool is 10 decimeters. How many square meters is the area covered with cement?
一个圆柱形水池的内壁和底面都要抹上水泥，水池底面直径是4米，水池深10分米．抹水泥的面积是多少平方米．
<gadget id="calculator">10 / 10</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 4 * 1</gadget>
<output>12.56</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">12.56 + 12.56</gadget>
<output>25.12</output>

<result>25.12</result>