A cylindrical swimming pool has a diameter of 40m and a depth of 2m. What is the area of the swimming pool in square meters?
一个圆柱形游泳池，直径40m，深2m，这个游泳池的占地面积是多少平方米？
<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">20 ** 2</gadget>
<output>400</output>

<gadget id="calculator">3.14 * 400</gadget>
<output>1_256</output>

<result>1_256</result>