Because the circumference of a circle: radius =2π (certain)

The diameter of a circle is proportional to its circumference.

Because circumference: diameter = π (certain)

The radius of the circle is out of proportion to the area of the bottom.

Because the radius is a, the bottom area is the square of π a.

The square of πa: a=πa, not necessarily. So out of proportion.

The diameter and radius are the same.

The radius of a circle is not proportional to its volume, so is its diameter. The principle is the same as the bottom area.

What about the bottom area and volume of the circle?

Judging from your sentence, it is out of proportion. If there is a condition: the height is certain, it is proportional. Because volume: bottom area = height (certain)

The upper bottom of the trapezoid is out of proportion to the area.

Because I don't know the bottom, and the upper bottom and the lower bottom are added and subtracted.

Judging the positive-negative ratio:

1. Judge whether one quantity changes and the other quantity changes.

2. Judge whether two quantities are addition, subtraction or multiplication and division. If it is addition and subtraction, it is out of proportion, if it is multiplication and division, it is

3. Determine whether it is proportional determination or product determination. If it is proportional, it must be proportional; The product must be inversely proportional.