Answer:
The length of the pillow in the shape of a wedge is 4 ft.
Explanation:
The formula for the volume of a wedge is:

Where b is the base, h is the height and L is the length.
The volume of the pillow is:

Then we equate both equations and obtain:

We know b and h. So we cleared L.

So



The length of the pillow is 4 ft.