In the rectangle below, find the area of the shaded triangle.

1. Identify the base and height of the shaded triangle

The shaded triangle has its base on the top edge of the rectangle. The length of this base is given as $9\text{ cm}$. The height of the triangle corresponds to the height of the rectangle, which is $8\text{ cm}$.

2. Calculate the area of the shaded triangle

$\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}$
$\text{Area} = \frac{1}{2} \times 9 \times 8 = 36\text{ cm}^2$