Answer:
Length = 23 feet
Explanation:
Formula to get the area of a Rectangle
Area = Length x width ( Length x breadth)
if Area = 69 feet and Width = 3 feet Length = x
Area = Length x Width
substitute the values
69 square feet = X feet x 3 feet
69 = 3x
69/3 = 3x/3
23 = X
Length = 23 feet
Proof: 23 X 3 = 69 ✓