Which of the following quantities are directly proportional:

The area of a rectangle and its length, if its width is 6 cm.

Area ∝ Length.

Step-by-step explanation:

If the length of a rectangle is L and width is W, then the area of the rectangle is given by A = LW.

Now, it is given that the width of a rectangle is constant and it is 6 cm.

Therefore, the relation between the length of the rectangle in cm with the area of the rectangle in cm² will be A = 6L.

So, it is clear from the above relation that Area (A) is proportional with its length (L) and the constant of proportionality is 6. (Answer)