Question

A paper cone has a base diameter of 8cm and height 3cm. If d cone is cut and opened out into d sector of a circle, what is d angle of d sector?

Answer 1

" ... is cut and opened out into d sector..."
I would expect to have only one sector.
Check your typing.

Answer 2

Since the slant height (5) is the radius of the original circle, the angle is
(8π)/(10π) * 2π = 8π/5