Judge whether the two quantities in the following questions are in inverse proportion, and explain the reason: the triangle has a certain area, its bottom and height

Judge whether the two quantities in the following questions are in inverse proportion, and explain the reason: the triangle has a certain area, its bottom and height

Base x height = 2 triangle areas (certain)
The area of a triangle is fixed, and its base is inversely proportional to its height

1. Area and radius of circle, 2. Height of triangle

1. Area and radius of the circle,
The area and radius of a circle are not in direct proportion. The ratio of the area and radius of a circle is not constant
2. The area and height of a triangle are not in direct proportion. The ratio of area and height is equal to half of the bottom. The bottom is uncertain, so it is not in direct proportion

Judge whether the two quantities in each of the following questions are in positive proportion, and explain the reasons. 1. The bottom of the triangle is fixed, its area and height. 2
2. The total working time is fixed, the production time of each part and the number of parts. 3. The length of a rope is fixed, the length of the cut and the remaining length

1. The base of a triangle is fixed, and its area and height are in direct proportion to s = 1 / 2 * a * H
2. The total working time is fixed, and the production time of each part is inversely proportional to the number of parts
3. The length of a rope is fixed, and the cut length is out of proportion to the remaining length