Answer:
Explanation:
1.
Area of shaded region = Area of external rectangle - Area of internal rectangle
2.
Let the width of the rectangle be x inches.
Therefore, length of the rectangle = (x + 3) inches
A.
Area of rectangle
B.
Width of rectangle = 4 inches
Length of rectangle = 4 + 3 = 7 inches
Area of rectangle = 7*4 = 28 square inches.