If a cylinder has a base radius of 1 decimeter and a height of 3 decimeters, what is its surface area in square decimeters?
一个圆柱体的底面半径是1分米、高3分米，它的表面积是多少平方分米．
<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">3.14 * 2</gadget>
<output>6.28</output>

<gadget id="calculator">2 * 3.14 * 1 * 3</gadget>
<output>18.84</output>

<gadget id="calculator">6.28 + 18.84</gadget>
<output>25.12</output>

<result>25.12</result>