To find the area of the shaded section in the diagram, we can break it down into simpler geometric shapes. The figure seems to be composed of a rectangle at the bottom and a trapezium or triangular shape on top.

Step-by-step calculation:

1. Bottom Rectangle (ABFG):

   • Length $= 12 \, \text{cm}$ (from $A$ to $G$).
   • Height $= 9 \, \text{cm}$ (from $A$ to $B$).

   Area of rectangle = $\text{length} \times \text{height} = 12 \times 9 = 108 \, \text{cm}^2$.

2. Top Trapezium or Triangle (CDEF):

   • The base of the trapezium at the bottom is $12 \, \text{cm}$ (from $C$ to $F$).
   • The top length is $6 + 6 = 12 \, \text{cm}$ (from $C$ to $E$).
   • The total height of the trapezium is $18 \, \text{cm}$ (from $C$ to $D$) minus the height of the rectangle $9 \, \text{cm}$, so the height of the trapezium is $18 - 9 = 9 \, \text{cm}$.

   For a trapezium: $\text{Area} = \frac{1}{2} \times ( \text{Base}_1 + \text{Base}_2 ) \times \text{Height}$ Substituting the values: $\text{Area} = \frac{1}{2} \times (12 + 12) \times 9 = \frac{1}{2} \times 24 \times 9 = 108 \, \text{cm}^2$

3. Total Area of the Shaded Section: The shaded area consists of the rectangle and the trapezium on top. Adding the areas: $\text{Total Area} = 108 \, \text{cm}^2 + 108 \, \text{cm}^2 = 216 \, \text{cm}^2$

Thus, the area of the shaded section is 216 cm².

Would you like further clarification on any step? Here are some related questions to explore:

1. How do you find the area of a trapezium in general cases?
2. What are other ways to divide complex shapes into simpler ones?
3. What is the difference between finding the area of a triangle and a trapezium?
4. How would the total area change if the dimensions of the rectangle were different?
5. What is the formula for the area of a complex polygon?

Tip: Always try breaking down complex figures into simpler, known shapes to make area calculations easier.