To put a wire hoop on the outside of a cylindrical bucket with a bottom radius of 10 cm, and the joint part is 6 cm, how many centimeters of wire is needed?
要在底面半径是10厘米的圆柱形水桶外面打上一个铁丝箍，接头部分是6厘米，需用铁丝多少厘米．
<gadget id="calculator">3.14 * 2 * 10</gadget>
<output>62.8</output>

<gadget id="calculator">62.8 + 6</gadget>
<output>68.8</output>

<result>68.8</result>