A cylinder with a base circumference of 25.12 cm is a square when its sides are expanded. If it is cut in half along the diameter of the base, how many square centimeters will its surface area increase?
一个底面周长为25.12厘米的圆柱体，侧面展开是一个正方形，如果沿底面直径把它平均切成两半，它的表面积增加多少平方厘米．
<gadget id="calculator">25.12 / 3.14</gadget>
<output>8</output>

<gadget id="calculator">8 * 8</gadget>
<output>64</output>

<result>64</result>