If a cylinder with a base diameter of 6 cm and a height of 5 cm is cut into two half cylinders along the base diameter, how many square centimeters will the surface area increase?
把一个底面直径是6厘米，高是5厘米的圆柱体沿底面直径切开成两个半圆柱后，表面积增加了多少平方厘米．
<gadget id="calculator">6 * 5 * 2</gadget>
<output>60</output>

<result>60</result>