I saw such a problem in the "two-color class for primary school students" this afternoon. The bottom radius of the cone is 8 decimeters, and the ratio of height to bottom radius is 3: 2. What is the volume of this cone? Analysis: this is a question of proportional application ... "I figured it out without looking at the analysis, huh?" I haven't learned how to calculate the area of a cone. Then how can I solve this problem? I sighed, ready to continue to watch the analysis, and then I thought, will I be in the sixth grade soon after this summer vacation? If you can't even do the questions in this course. What kind of Olympics class am I? Is it not worthy of the name? Yes, I have to solve it myself. As usual, I must build a model in my mind before this kind of problem, but I am very cautious about this problem for fear of making mistakes. I drew a perspective effect of a cone on the paper. Take a closer look, huh? Isn't this figure the same as a triangle if it is a plane figure? Isn't the cubic area of this cone 1 of the area of a cylinder with the same base and height? I am ecstatic. The original cone area is also easy to find. As long as you know the height and bottom area of the cone, can't you get it? Back to this question, its condition tells you the radius of the bottom, which is equivalent to telling the area of the bottom. It says that the ratio of height to bottom radius is 3: 2, which means that the length of bottom radius is two-thirds of height. Isn't that height just radius ×3÷2= height? Therefore, the height is 12 decimeter, the bottom area is 200.96 cubic decimeter and the cone area is 200.96×12 ÷ 2 =1205.76 cubic decimeter. " Wow, I finally solved it. "I heaved a sigh of relief. Through this question, I also found that there are actually many things in mathematics, just like the area of a cone and the area of a triangle. In fact, you don't need to know all the calculation formulas, as long as you can understand them, you can also solve problems. Is it okay? No, modify it!