If a cylinder with a base diameter of 5 cm and a height of 12 cm is cut into two half cylinders along the diameter, what is the increase in surface area?
把一个底面直径为5厘米，高为12厘米的圆柱体沿直径切割成两个半圆柱，表面积增加多少．
<gadget id="calculator">5 * 12 * 2</gadget>
<output>120</output>

<result>120</result>