A cylinder has a base radius of 3 cm and a height of 8 cm, what is the surface area?
圆柱的底面半径3厘米，高8厘米，求表面积？
<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9 * 2</gadget>
<output>56.52</output>

<gadget id="calculator">3.14 * 3 * 2 * 8</gadget>
<output>150.72</output>

<gadget id="calculator">56.52 + 150.72</gadget>
<output>207.24</output>

<result>207.24</result>