Cone Question (1 Viewer)

[TearsOfFire]

A cone is made by joining together the radii of the sector of a circle of radius 16 cm. The radius of the base of the cone is 4 cm. Find:

i) The circumference
ii) The angle at the centre of the sector
iii) The curved surface of the cone


What I'm struggling to understand is how the shape is made.. Like which part of the sector of the circle is used to make the cone? If someone could draw the dimensions of the circle, or describe what it looks like, I'd really appreciate it (I can figure the answers out once I understand what the cone looks like)

Thanks in advance

 

[dolbinau]

edit: 4cm is radius of cone, I see.

 

[Timothy.Siu]

A cone is made by joining together the radii of the sector of a circle of radius 16 cm. The radius of the base of the cone is 4 cm. Find:

i) The circumference
ii) The angle at the centre of the sector
iii) The curved surface of the cone


What I'm struggling to understand is how the shape is made.. Like which part of the sector of the circle is used to make the cone? If someone could draw the dimensions of the circle, or describe what it looks like, I'd really appreciate it (I can figure the answers out once I understand what the cone looks like)

Thanks in advance

to make the cone they join the TWO radii on the SAME sector together
i) circumference of what? of the base of the cone? 8pi?
ii)umm angle would be 18pi/16=9/8pi RADIANS
iii)curved surface is the area of the sector i think? so 1/2x16^2x9/8pi=144pi units squared