A circle has a radius of 25. A circular sector, with an angle of 320 degrees at the center, is cut from the circle, and then rolled to form a cone. Find the volume of the cone.
Circle radius R = 25 ( "R" is also the slant height of a cone )
Sector arc = 320º
Cone radius r = 25(320/360)
Cone height h = sqrt(R2 - r2)
Cone volume V = 1/3(πr2h)