The cone shown has a diameter of 12 centimeters and a slant height of 8 centimeters. Which choice is closest to the total surface area? Use 3.14 to approximate pi.

Question

triciaal · Answer

using pythagorean theorem you can find the perpendicular height
area of the circle is pi *r^2  and you have the diameter which is twice the radius, r 
told to use pi = 3.14
what is the formula for the surface area of the cone?
plug your numbers and solve

triciaal · Answer

so, the perpendicular height is not needed for this problem.
The Surface Area formula is S = pi*r^2 + pi*r*l  where l is the slant height
Plug the numbers and simplify