If a cylinder with a height of 5 meters is sawed into two pieces, the surface area is increased by 10 square decimeters, what is the area of the original cylinder's bottom?
把高5米的圆柱体锯成两段，表面积增加了10平方分米，原来圆柱体的底面积多少平方分米．
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<result>5</result>