How many centimeters is the surface area of three cylindrical steel pipes with a bottom diameter of 4 cm reduced to a steel bar?

Should these 35 Chinese characters be "returned to the furnace" to form a sentence that everyone can understand? Don't form "Seoul", "Pyongyang" and "Seoul" again, lest you laugh your head off!

1, the diameter of the steel pipe is exactly the diameter of the steel pipe. How can the diameter of the bottom surface, the diameter of the top surface and the diameter of the side surface be different?

2. The steel pipe is cylindrical, how can it be cylindrical?

3. What does "Seoul City" mean? Who can read it?

4. Can three steel pipes be welded into a steel bar? What a joke! Three steel pipes can only be melted into one steel bar!

5. Surface area is a kind of area. Is the area measured in centimeters?

Give you 5 out of 35 words, and enjoy 7 words on average 1! That's interesting.