Answer:
7 feet
Explanation:
Assuming that the piece of painting is in the shape of a rectangle.
It is given that the width is 4 feet long and that the area is 28 feet².
We know that the Area of a rectangle is given by the formula length x width.
To find the length, we divide the area by the width.
Length = 28 ÷ 4 = 7 ft
So the length of the painting is 7 feet long.