The outer diameter of a drum is 6 decimeters. An iron hoop is added outside it. The length of the joint of the iron hoop is 0.3 decimeters. How long is this iron hoop?
一个圆桶的外直径是6分米，在它的外面加道铁箍，铁箍接头处长0.3分米，这道铁箍长多少分米？
<gadget id="calculator">3.14 * 6</gadget>
<output>18.84</output>

<gadget id="calculator">18.84 + 0.3</gadget>
<output>19.14</output>

<result>19.14</result>