If a cylinder with a base radius of 2 cm and a height of 5 cm is cut along the diameter of the base, what is the increase in surface area in square centimetres?
把一个底面半径是2厘米、高5厘米的圆柱沿底面直径切开，表面积增加了多少平方厘米．
<gadget id="calculator">5 * 2 * 2 * 2</gadget>
<output>40</output>

<result>40</result>