Given that (1)/(4) of the rectangle is shaded, we multiply the total area by this fraction.

The area of a rectangle is given by the formula $\text{Area} = \text{length} \times \text{width}$.

$$\text{Area} = 8 \text{ cm} \times 9 \text{ cm} = 72 \text{ cm}^2$$

Given that $\frac{1}{4}$ of the rectangle is shaded, we multiply the total area by this fraction.

$$\text{Shaded Area} = \frac{1}{4} \times 72 \text{ cm}^2 = 18 \text{ cm}^2$$

The unshaded area is the total area minus the shaded area.

$$\text{Unshaded Area} = \text{Total Area} - \text{Shaded Area}$$ $$\text{Unshaded Area} = 72 \text{ cm}^2 - 18 \text{ cm}^2 = 54 \text{ cm}^2$$

The unshaded part of the rectangle is $\text{54 cm}^2$.