Answer:
28.5 units²
Explanation:
You are correct.
You divided the figure into a square, a rectangle and a triangle.
You can also just divide into a rectangle and a triangle as I did below, and there are other ways of dividing the figure to find the area.
Bottom rectangle: 8 units by 3 units
Top triangle: base = height = 3 units
total area = area of rectangle + area of triangle
total area = length × width + base × height / 2
total area = 8 units × 3 units + 3 units × 3 units / 2
total area = 24 units² + 4.5 units²
total area = 28.5 units²