a cone that has a base diameter-8cm and height-3cm is cut into a circle's sector, what is the angle of the sector

1 answer

If radius of cone is 4 cm, and its height is 3 cm, then the "slant" length of the cone is 5 cm
(3^2 + 4^2 = 5^2)

If cut open , this translates into a "pac-man" game looking sector with arc length equal to the circumference of the base of the cone and its radius equal to the "slant" length of the cone.
radius of sector = 5 cm
arc = 8π cm

arc = rØ , where Ø is the sector angle in radians
8π = 5Ø
Ø = 8π/5 radians or 288°