First, the rectangle:
We have the measurements of a length of 4, and width of 2. The area of a rectangle is Length times Width, therefore:
4x2=8 ft squared for the rectangle.
Now the Triangle:
We see that the whole left side is 4ft, and that the rectangle's width is 2ft; therefore, the left side of the triangle is 2 ft (4-2).
The area of a triangle is 1/2Base times Height. The base is 4, and the height is 2; therefore:
1/2x4x2=4 ft squared.
Now we add our areas for the total:
4+8=12 ft squared
I hope this Helps!