Question

how do i find the surface area of a right cone? with the measurements of 5ft as the radus and 12ft as a hight

Answer 1

do we include the base area?

Answer 2

if you cut the cone up its length and splay it out; we get a part of a circle; with radius 12 and arc length of 5

Answer 3

the total area of the circle would be 2pi(12) = 24pi

24pi/5 is the length of the arc

area of a sector is: (radian angle)r^2/2

Answer 4

thank you

Answer 5

arc length = angle(r)

5 = angle(12)

angle = 5/12 ; in radians

5(12)^2
area = ------- = 5(6) = 30 if I did it right :)
12*2

Answer 6

if that includes that area of the base then add on another 25pi

Answer 7

thanks