1. A cylinder consists of two bottom faces and one side face, and has countless heights. For example: flashlight battery glass teapot

A cone consists of a bottom surface and a side surface, with only one height. For example: ice cream cone Christmas hat pyramid

2. lateral area of cylinder = perimeter of bottom surface * high surface area = bottom area *2+ lateral area formula: S side =CH.

3. Cylinder volume = bottom area = height formula: V=SH

4. Volume of cone = bottom area * height * one-third formula: one-third SH

2. Positive proportion and inverse proportion

1. Judge whether it is in direct proportion: (1). If one quantity increases or decreases, the other quantity will also increase or decrease accordingly. (2) Their ratio (i.e. quotient) is fixed (i.e. constant).

2. In direct proportion, all points are on the same straight line.

3. Judge whether it is inversely proportional: (1). One quantity increases and the other quantity decreases. (2) Their product must be constant.

4. All points can be connected into a curve in inverse proportion.

Only when the length and width are drawn in the same proportion can the painting be like.

6. The preceding paragraph of the scale is simplified to 1 (except for small parts). The units of length indicated in the preceding paragraph and the latter item must be units of the same level.

If you need examples, choose a few topics in the book.

Absolutely original, that's what I wrote, I hope to adopt it! !