Final answer:
Wedding cakes and tiered cakes are often presented on square plates which provide symmetry and stability, complementing their structure and design.
Step-by-step explanation:
The types of cakes that usually go on a square plate are wedding cakes and tiered cakes. These cakes are often displayed on square plates, especially in formal settings like weddings, where their structure and shape are complemented by the symmetry and stability of square presentation plates. Imagining the artwork from figure 4.4.9 or 6.4.9, we can visualize that cakes with intricate designs and multiple layers, such as wedding cakes, often require the support and space provided by square plates to be properly showcased and served.