Formula: The area of a circle is equal to π times the square of radius, so the area is proportional to the square of radius.

correct

Formula: The area of a rectangle is equal to the length multiplied by the width, the length is a fixed value, and the area is positively correlated with the width.

mistake

The growth speed of each tree is different, and the growth height of different trees is not proportional to time.

correct

The unit price of Haikou Evening News is fixed, the order quantity increases, and the total amount of money is directly proportional to the quantity.