A cylindrical tin bucket without a lid is 45 decimeters high and has a bottom circumference of 9.42 decimeters. What is the minimum square decimeter of iron sheet used to make this bucket?
一个无盖的圆柱形铁皮水桶，高45分米，底面周长是9.42分米．做这个水桶至少用铁皮多少平方分米？
<gadget id="calculator">9.42 * 45</gadget>
<output>423.9</output>

<gadget id="calculator">9.42 / 3.14 / 2</gadget>
<output>1.5</output>

<gadget id="calculator">1.5 ** 2</gadget>
<output>2.25</output>

<gadget id="calculator">3.14 * 2.25</gadget>
<output>7.065</output>

<gadget id="calculator">423.9 + 7.065</gadget>
<output>430.965</output>

<result>430.965</result>