To make a cylindrical tin bucket without a cover, the diameter of the bottom surface is 4 decimeters, and the height is 6 decimeters. How much iron is needed to make this tin bucket?
要做一个无盖的圆柱形铁皮水桶，底面直径是4分米，高6分米，做这个铁皮水桶至少需要多少铁皮？
<gadget id="calculator">3.14 * 4 * 6</gadget>
<output>75.36</output>

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

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

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<gadget id="calculator">75.36 + 12.56</gadget>
<output>87.92</output>

<result>87.92</result>