Which of the following is not represented on the h-r diagram?
a. red giants
b. white dwarfs
c. main sequence stars
d. green giants
e. all of the above are found on the h-r diagram

The answer is d, green giants.

The HR diagram is a key tool in tracing the evolution of stars. Stars begin their life on the main sequence, but then evolve off into red giant phase and supergiant phase before dying as white dwarfs or some more violent endpoint.

Dis an orderly way to conduct research 

It’s letter b because the area of the trapezoid is 72