A cylinder is expanded to form a square. The height of the cylinder is 18.84 decimeters. What is the area of the base of the cylinder?
把一个圆柱侧面展开是正方形，这个圆柱的高是18.84分米，这个圆柱的底面积是多少．
<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>