If the height of a cylinder increases by 2 centimeters, the surface area increases by 12.56 square centimeters. What is the area of the base of the cylinder in square centimeters?
一个圆柱的高增加2厘米，则表面积增加了12.56平方厘米，这个圆柱的底面积是多少平方厘米．
<gadget id="calculator">12.56 / 2 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<result>3.14</result>