To find the area of the shaded figure, we will follow these steps:

1. Calculate the area of the rectangle: The dimensions are given as $21.6 \times 12$. $\text{Area of rectangle} = 21.6 \times 12$

2. Calculate the area of the right triangle: The legs of the triangle are $9.6$ and $7.2$. The area of a triangle is given by: $\text{Area of triangle} = \frac{1}{2} \times \text{base} \times \text{height}$

3. Find the shaded area: Subtract the area of the triangle from the area of the rectangle: $\text{Shaded area} = \text{Area of rectangle} - \text{Area of triangle}$

Let's calculate this now.The area of the shaded figure is approximately 224.64 square units.

Would you like more details or have any questions?

Here are some related questions:

1. How do you find the area of different types of triangles?
2. What is the formula for calculating the area of irregular polygons?
3. How do you apply the Pythagorean theorem to find missing sides in triangles?
4. How can you calculate the perimeter of composite shapes?
5. How is the area of a trapezoid calculated?

Tip: Always check that all units are consistent (e.g., lengths are all in the same units) before calculating areas or perimeters.