Let's first start by finding the area of the bigger rectangle.
Area = Length × Width
Area = (4) (3)
Area = 12 ft².
Now, let's find the area of the smaller rectangle.
Area = Length × Width
Area = (4) (1)
Area = 4 ft².
Finally, we need to add the areas of both of the figures to fo find the area of the whole figure.
12 ft² + 4 ft² = 18 ft².