Call the region in the

-

plane, bounded by

and

,

. Then the volume under the given surface is
The perimeter of any figure, is all its sides summed up
now, notice the picture below, using the 30-60-90 rule, that's "x"
now, get the other sides, since you know what "x" is, and sum them up, that's the perimeter
Now, there are 365 (excluding leap years) in a year, so, 275 days is not even a year, but is 275/365 of a year, or 55/73 of a year.