When plotted on an H-R diagram, how does a star move when transitioning from the main sequence to a red giant?

Answer

Upward and to the right

The move to the giant phase involves a significant temperature drop (moving right) but a massive increase in radius and luminosity (moving up), resulting in a steep diagonal climb on the diagram.

When plotted on an H-R diagram, how does a star move when transitioning from the main sequence to a red giant?
astronomystarsstellar evolutionmain-sequencered giant