If a cylindrical steel material with a ground diameter of 8 cm and a height of 5 cm is cut in half along the diameter and height of the bottom surface, how many square centimeters will the surface area increase?
把一个地面直径是8厘米，高5厘米的圆柱形钢材，沿底面直径和高切成两半，表面积增加了多少平方厘米．
<gadget id="calculator">8 * 5 * 2</gadget>
<output>80</output>

<result>80</result>