For angle A, you need to do 180-130 which is 50
for angle B, you need to do 180- 90 - 50 which is 40
for angle C, you need to do 180 - 60 - 40 which is 80
If you want me to explain you with further details with how exactly I got those answers and how I knew what to do, then ask me.
I wanna say it’s d because of the way it’s set up, i hope this helps if not i’m really really sorry
Answer:
You have a chance to get the pink marble at least once.
Make a change of coordinates:


The Jacobian for this transformation is

and has a determinant of

Note that we need to use the Jacobian in the other direction; that is, we've computed

but we need the Jacobian determinant for the reverse transformation (from

to

. To do this, notice that

we need to take the reciprocal of the Jacobian above.
The integral then changes to
