cylindrical chimney has a base radius of 8 cm and a height of 85 cm. To make a section of such a chimney, at least how many square centimeters of iron sheet is needed.
一种圆柱形的烟囱，底面半径8厘米，高85厘米．做一节这样的烟囱，至少需要多少平方厘米的铁皮．
<gadget id="calculator">2 * 3.14 * 5 * 85</gadget>
<output>2_669</output>

<result>2_669</result>