Ineed with this one because i got my answers wrong

40+60+y=180
y=180-100
y=80

A triangle is 180° so you add all the numbers available in the trianle and minus it with 180 to see what is left from the 180 and that will be the inner angle answer

X=180-80=100

A straight line is also 180° so if u minused one side which in our case is 80 u will get the rest which is the outer angle

Im pretty sure it would be 6 purple rectangles.

2160ft^3 i think you could use a formala to you out with this in the future