The side view of a cylinder is a square. It is known that the area of one of its bases is 5 square decimeters. What is its surface area?
一个圆柱的侧面展开图是正方形，已知它的一个底面积是5平方分米，它的表面积是多少．
<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">20 * 3.14</gadget>
<output>62.8</output>

<gadget id="calculator">10 + 62.8</gadget>
<output>72.8</output>

<result>72.8</result>