Answer:
A = 108 feet²
Step-by-step explanation:
Let the width is b.
Length = 3+b
Perimeter of the rectangle, P = 42 ft
Perimeter = 2(l+b)
42 = 2 (3+b+b)
21 = (3+2b)
21-3 = 2b
18 = 2b
b = 9 feet
Length, l = 3+9 = 12 feet
Area of the rectangle,
A = lb
So,
A = 12 × 9
A = 108 feet²
So, the area of the rectangle is 108 feet².
