There is a section of cuboid steel, its cross section is 10 square centimeters, if it is cut into 3 sections, the surface area increases by how many cm**2.
有一段长方体钢材，它的横截面是10平方厘米，把它截成3段，表面积增加了多少cm**2．
<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<result>40</result>