Expand the side of a cylinder to get a square. The height of the cylinder is 31.4 cm. What is the side area of the cylinder?
把一个圆柱的侧面展开，得到一个正方形，圆柱的高是31.4厘米，这个圆柱的侧面积是多少？
<gadget id="calculator">31.4 * 31.4</gadget>
<output>985.96</output>

<result>985.96</result>