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Begging math diary to start.
Today, I saw such a problem in the training of Mathematics 1+2. A cubic casting with a bottom area of 648 square centimeters, what is the remaining three-dimensional graphic area after removing the largest cylinder and taking the opposite side as the bottom?

Seeing this topic, I was very confused and thought: just say a bottom area, how to do it? My mother sitting in the chair looked at it, smiled at me and said, "Hum, she can't even do this problem."

I know my mother used the goad method, in order to irritate my competitive spirit and let me finish this problem. In order to make my mother think that her provocation was successful, I crustily skin of head did it, but I couldn't figure it out. But I'm not discouraged. I persisted and finally succeeded.

According to the drawing (to be drawn), it can be found that when a cylinder is cut off, a hole with the same size as the original cylinder will come out. Although the volume of the hole is the same as that of the cylinder, their surface areas are not the same, but the areas of the two bottoms are smaller than that of the original cylinder.

Therefore, the remaining graphic area should be equal to the area of the six faces of the cube minus the two bottom faces of the cylinder+the side faces of the cylinder.

The formula is 628× 6-628× 3.14 ÷ 4× 2+628× 3.14.