After the side of a cylinder is cut along the height, a square is obtained. If the height of the cylinder is 6.28 decimeters, find the area of the base of the cylinder in square decimeters.
一个圆柱的侧面沿高切开后，得到一个正方形，若圆柱的高是6.28分米，求圆柱的底面积多少平方分米．
<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<result>3.14</result>