There is a cylinder whose lateral expansion is exactly a square with a side length of 31.4 cm, find its surface area.
有一个圆柱体侧面展开正好是一个边长31.4厘米的正方形，求它的表面积．
<gadget id="calculator">31.4 * 31.4</gadget>
<output>985.96</output>

<gadget id="calculator">31.4 / 3.14 / 2</gadget>
<output>5</output>

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

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

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

<result>1_142.96</result>