If a cylinder with a base diameter of 10dm is expanded to form a square, what is the surface area of the cylinder?
若将一个底面直径为10dm的圆柱体的侧面展开，得到一个正方形，则这个圆柱体的表面积是多少．
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25 * 2</gadget>
<output>157</output>

<gadget id="calculator">3.14 * 10</gadget>
<output>31.4</output>

<gadget id="calculator">31.4 * 31.4</gadget>
<output>985.96</output>

<gadget id="calculator">157 + 985.96</gadget>
<output>1_142.96</output>

<result>1_142.96</result>