The problem reduces fairly simply to \"area of base * 30\" (provided the silo doesn't grow out above the roof of the barn, which it doesn't seem to be doing.)
So the question is, what's the area of the base?
The face against the barn is 10 feet wide, or 5 feet to each side of the centerline, and it's 5 feet from the center. That means the angle between the center of the silo and the barn-silo intersection is 45 degrees to each side, or 90 degrees total, and the radius of the silo is 5*sqrt(2).
One way to think of the silo shape is as 3/4 of a circle (everything but the 90 degrees that faces the barn, in dark gray in the image I'll upload as soon as they're done doing maintenance on the server) plus a triangle (the 90 degrees that faces the barn, in light gray on the same image.)
The area of a whole circle would be pi*r^2, or pi*(5*sqrt(2))^2, or pi*50. So 3/4 of the circle has an area of 150*pi/4, or 75*pi/2. The area of the triangle is base*height/2, or 10*5/2 = 25. So the sum total area is 25+75*pi/2, and the overall volume is 30*(25+75*pi/2) or approximately 4284.29 cubit feet, provided I've done all my calculations right.
![Image](http://x85.xanga.com/542f35f132032237507406/w187736229.gif)