Where are the physically enormous Giants and Supergiants located on the H-R diagram?

In the upper-right portion, indicating high luminosity and low temperature.

The Giant and Supergiant regions are situated above the Main Sequence, primarily populating the upper-right section of the H-R diagram. Stars located here exhibit immense luminosity—meaning they radiate a great deal of energy—but possess relatively low surface temperatures. To achieve such high output with lower temperatures, these stars must possess enormous physical sizes, having expanded significantly after exhausting the hydrogen fuel in their cores. Supergiants are the most luminous of these, found at the very top, while Giants appear slightly below them, often looking reddish or orange due to their cooler surfaces compared to Main Sequence stars of comparable luminosity.