Find the height and radius of a cup that will require the least amount of paper.?

Question

A cone-shaped paper drinking cup is to hold 55 of water. Find the height, , and radius of the cup, , that will require the least amount of paper.

Carry out all calculations exactly, round to 2 decimal places the final answer only.

Answer 1

Diameter and height will be equal in this case. As V = 55
pi r^2. 2r/3 = 55 giving r^3 = 165/4

r = 3.455

h = 2r = 6.91

Answer 2

use finished floor section=pir^2 +pirs =pir(r+s) I got here up with radius 5cm top 12cm This equals 314.16cm^3 attempt to get closer on your 100cm^3 using floor section to equivalent quantity of water V=of a cone= a million/3pir^2h or 0.2618d^2h