cylinder with a height of 3 cm is cut into two identical half cylinders along the diameter, and the surface area at this time increases by 24 square centimeters. What is the original area of the base of this cylinder in square centimeters?
一个高3厘米的圆柱，沿着直径切成两个完全一样的半圆柱，这时的表面积增加了24平方厘米，这个圆柱原来的底面积是多少平方厘米？
<gadget id="calculator">24 / 2 / 3 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>