For energy conservation and environmental protection, a certain place launched the project of "every family builds a biogas digester". A cylindrical biogas digester with a bottom diameter of 3m and a height of 2.5m was dug out, and a layer of cement was spread around it and the bottom of the pond. area of cement.
某地为节能环保特推出"家家建沼气池"工程，挖出一个底面直径为3m，高为2.5m的圆柱形沼气池，并在它的四周和池底抹上一层水泥，求抹水泥的面积．
<gadget id="calculator">3.14 * 3 * 2.5</gadget>
<output>23.55</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) ** 2</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">3.14 * (9/4)</gadget>
<output>7.065</output>

<gadget id="calculator">23.55 + 7.065</gadget>
<output>30.615</output>

<result>30.615</result>