A cone has a lateral surface area of 540pi and a slant height of 36. Unrolling the curved surface gives a circular sector with center angle n degrees. Find n.
The slant height wil be the radius of the sector......we have
540 pi = (1/2) r^2 ( theta ) in rads
1080 pi = 36^2 ( theta )
1080 pi /36^2 = (theta)
To convert this into degrees :
(1080 pi) /36^2 * 180° / pi = 150°