What are some ways I can study for my math test?

There is a variety of so many websites you can use to study. Here is some I prefer:

Khan Academy

Q u i z l e t - you can make your own study guides (they weren't letting me write it, so I wrote it like this)

If you are offline, or do not want to use internet, you can:

Make Flashcards

Study out of a textbook or book that teaches you about it.

I hope this helps!

the answer is c.

step-by-step explanation:

m∠a is 90°

m∠b is 40°