The diameter of the base of a cylinder is 2 decimeters, and the side view is a square. What is the lateral area of the cylinder?
一个圆柱的底面直径是2分米，侧面展开图是正方形，这个圆柱的侧面积是多少？
<gadget id="calculator">3.14 * 2</gadget>
<output>6.28</output>

<gadget id="calculator">6.28 * 6.28</gadget>
<output>39.4384</output>

<result>39.4384</result>