The radius of the base is 4 cm and the height is 6 cm. Calculate the surface area of the cylinder.
底面半径是4厘米，高是6厘米，计算圆柱体的表面积．
<gadget id="calculator">2 * 3.14 * 4 * 6</gadget>
<output>150.72</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>