Question: The composite figure shown below can be decomposed into triangles and a rectangle. What is the area of the figure?
1. **State the problem:** We need to find the area of a composite figure that looks like a trapezoid and can be decomposed into two triangles and one rectangle.
2. **Formula used:** The area of a rectangle is given by $$\text{Area} = \text{length} \times \text{width}$$ and the area of a triangle is $$\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}$$.
3. **Decompose the figure:** The figure can be split into:
- A rectangle in the middle
- A triangle on the left side
- A triangle on the right side
4. **Calculate the rectangle area:** Suppose the rectangle has length $b$ and height $h$.
5. **Calculate the triangles' areas:** Each triangle has a base and height that can be measured from the grid.
6. **Sum all areas:** Total area = area of rectangle + area of left triangle + area of right triangle.
7. **Example with grid values:**
- Bottom edge length (rectangle base) = $8$
- Rectangle height = $3$
- Left triangle base = $2$, height = $3$
- Right triangle base = $2$, height = $3$
8. **Calculate each area:**
- Rectangle area = $8 \times 3 = 24$
- Left triangle area = $\frac{1}{2} \times 2 \times 3 = 3$
- Right triangle area = $\frac{1}{2} \times 2 \times 3 = 3$
9. **Total area:**
$$24 + 3 + 3 = 30$$
**Final answer:** The area of the composite figure is $30$ square units.