If a cone with a base circumference of 15.7 cm and a height of 6 cm is cut into two parts of equal size along the height, how much does the surface area increase in square centimeters?
把一个底面周长15.7厘米，高6厘米的圆锥沿高剖成大小相等的两部分，表面积增加多少平方厘米．
<gadget id="calculator">15.7 / 3.14</gadget>
<output>5</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">5 * 3 * 2</gadget>
<output>30</output>

<result>30</result>