After cutting a cylinder with a base radius of 3 decimeters and a height of 15 decimeters into an approximate cuboid, how many square decimeters will the surface area increase from the original?
把一个底面半径是3分米，高是15分米的圆柱，切拼成一个近似的长方体后，表面积比原来增加多少平方分米？
<gadget id="calculator">15 * 3 * 2</gadget>
<output>90</output>

<result>90</result>