The answer to the math exercise book written by the teaching and research section of the sixth grade Zhejiang Provincial Department of Education.
The first page, the first big problem: circle triangle, triangle circle, the second big problem, the first one is connected with the third one, the second one is connected with the fourth one, the third one is connected with the fourth one, the fourth one, the second one, the fifth one, the sixth one, the sixth one, the fifth one, the third big problem, the figure formed by rotating the following figure is cylindrical, and there are one or six cones.