Given that the diameter of the base of the cylinder is 8 cm and the height is 6 cm, find its surface area.
已知圆柱的底面直径是8厘米，高是6厘米，求它的表面积．
<gadget id="calculator">3.14 * 8 * 6</gadget>
<output>150.72</output>

<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16 * 2</gadget>
<output>100.48</output>

<gadget id="calculator">150.72 + 100.48</gadget>
<output>251.2</output>

<result>251.2</result>