A cylindrical piece of wood with a base radius of 5cm and a length of 15m is sawn into three 5m-long cylinders. How much does the surface area increase?
一根圆柱形木料，底面半径是5cm，长是15m，锯成5m长的3段圆柱，表面积增加多少？
<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25 * 4</gadget>
<output>314</output>

<result>314</result>