The volume of a cone is certain. The area of the bottom of a cone is not proportional to its height. Why? The length of the road is fixed every day. The length of the road is not proportional to the number of days. Why? Come back!

The volume of a cone is certain. The area of the bottom of a cone is not proportional to its height. Why? The length of the road is fixed every day. The length of the road is not proportional to the number of days. Why? Come back!

1. The area of the base of a cone is inversely proportional to its height because the product is a constant
2. The length is proportional to the number of days, because the ratio is a fixed value

According to the relationship between the volume, the area of the bottom and the height of the cylinder, how can we get two positive proportions?

Cylinder volume △ height = bottom area (fixed), that is: the bottom area is fixed, the cylinder volume and height are in direct proportion
The volume of the cylinder △ the area of the bottom = the height of the cylinder

When the volume, bottom area and height of a cylinder are fixed, the other two quantities are in direct proportion, and when they are fixed, the other two quantities are in inverse proportion

When the bottom area is fixed, the height is directly proportional to the volume. When the height is one, the bottom area is directly proportional to the volume. When the volume is fixed, the height is inversely proportional to the bottom area