The outer diameter of the mouth of a washbasin is 42 centimeters. If it is buckled on the desktop, how many square centimeters is the covered area of the desktop?
用一个脸盆盆口的外围直径是42厘米，如果将它扣倒在桌面上，那么桌面被盖住的面积是多少平方厘米？
<gadget id="calculator">42 / 2</gadget>
<output>21</output>

<gadget id="calculator">21 ** 2</gadget>
<output>441</output>

<gadget id="calculator">3.14 * 441</gadget>
<output>1_384.74</output>

<result>1_384.74</result>