A cylindrical teacup with a bottom diameter of 6 cm and a height of 20 cm is now packed in a cuboid carton. How many square centimeters of cardboard should the carton be at least?
一个圆柱形茶杯，底面直径6厘米，高20厘米，现在装在一个长方体的纸盒内，纸盒至少要用多少平方厘米的硬纸板？
<gadget id="calculator">6 * 20</gadget>
<output>120</output>

<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<gadget id="calculator">120 + 120 + 36</gadget>
<output>276</output>

<gadget id="calculator">276 * 2</gadget>
<output>552</output>

<result>552</result>