If a cylinder with a base radius of 4 cm and a height of 10 cm is equally divided into two half cylinders, how many square centimeters will the surface area increase?
把一个底面半径是4厘米，高是10厘米的圆柱平均分成两个半圆柱后，表面积增加了多少平方厘米．
<gadget id="calculator">4 * 2 * 10 * 2</gadget>
<output>160</output>

<result>160</result>