A biscuit box in the shape of a cylinder has a base diameter of 20 cm and a height 10 cm greater than the diameter. To stick trademark paper on its side, the area of the trademark paper is at least how many square centimeters.
一个圆柱形状的饼干盒，底面直径是20厘米，高比直径多10厘米．要在它的侧面贴上商标纸，商标纸的面积至少是多少平方厘米．
<gadget id="calculator">20 + 10</gadget>
<output>30</output>

<gadget id="calculator">3.14 * 20 * 30</gadget>
<output>1_884</output>

<result>1_884</result>