If a cylinder with a base diameter of 5 cm and a height of 15 cm is cut into two half cylinders along the diameter, how much is the surface area increased?
把一个底面直径为5厘米，高为15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 * 15 * 2</gadget>
<output>150</output>

<result>150</result>