If a cylinder with a base radius of 4 cm and a height of 5 cm is cut in half along the diameter of the base, its surface area will increase by how many square centimeters.
一个底面半径4厘米，高5厘米的圆柱体，如果沿底面直径把它平均切成两半，它的表面积增加多少平方厘米．
<gadget id="calculator">2 * 4 * 5 * 2</gadget>
<output>80</output>

<result>80</result>