The height of a cylinder is twice the diameter of the base. After cutting the cylinder into two pieces of the same size along the diameter, the surface area increases by 40 square centimeters. What is the surface area of one piece in square centimeters?
一个圆柱的高是底面直径2倍，将这个圆柱沿直径切成两个大小一样两块后，表面积增加了40平方厘米，其中一块的表面积是多少平方厘米．
<gadget id="calculator">4 * 3.14 * 2.5</gadget>
<output>31.4</output>

<gadget id="calculator">3.14 * 2.5</gadget>
<output>7.85</output>

<gadget id="calculator">40 / 2</gadget>
<output>20</output>

<gadget id="calculator">31.4 + 7.85 + 20</gadget>
<output>59.25</output>

<result>59.25</result>