Cut a cylinder with a base radius of 5 cm and a height of 6 cm into several equal parts along the diameter and assemble it into an approximate rectangle. How much does the surface area increase?
把一个底面半径是5厘米，高是6厘米的圆柱沿直径切割成若干等份后拼成一个近似的长方形，表面积增加了多少？
<gadget id="calculator">2 * 5 * 6</gadget>
<output>60</output>

<result>60</result>