The base area of a cylinder is 12.56 square decimeters, and the height is 7 decimeters. What is the side area of the cylinder?
一个圆柱的底面面积是12.56平方分米，高是7分米，这个圆柱的侧面积是多少平方分米．
<gadget id="calculator">2 * 3.14 * 2 * 7</gadget>
<output>87.92</output>

<result>87.92</result>