Q is 150. Supplementary angles must add to equal 180
With the information given we have:

Where W is the weight, k is the proportionality constant and r is the radius of the can's radus. Remember that the weight varies jointly so this key word means that you need to multiply the mentiones parameters by a proportionality constant k.
We simply need to reorganize the expression and isolate k for the frst answer:

Replacing by all the appropiate values we get:

For the second part knowing k we have:
-3y = -2x -6
Y= 2/3x + 2
When x= 3
Y= 2/3(3) + 2
Y= 2+2 = 4
(3,4)
When x= 6
Y=2/3(6)+2
Y= 4+2 = 6
(6,6)
When x= 12
Y= 2/3(12) + 2
Y= 8+2=10
(12,10)
It would be better if you've attached the figure its angle I should calculate. But I'll help you with some advice. You can find application in the internet that will calculate any angle by different ways. Just search your question, it will be first link