A cylinder with a base radius of 5 cm and a height of 10 cm, the base is divided into many equal sectors, and then cut and assembled into an approximate cuboid, how much does the surface area increase?
一个底面半径5厘米，高10厘米的圆柱体，底面分成许多个相等的扇形，再把它切拼成一个近似的长方体，表面积增加了多少？
<gadget id="calculator">5 * 10 * 2</gadget>
<output>100</output>

<result>100</result>