Question

"If the radius of the closed cone is doubled, show algebraically how this affects the surface area in comparison to the original cone."
How do I do this question?

Answer 1

Answer:

It would help to have the cone area formula:

Area = PI * radius * slant height

Let's say the height is 12cm radius is 5 cm

which makes the (slant height)^2 = 12^2 + 5^2 = 169

slant height = 13

and surface area = PI * 5 * 12 =  188.4955592154

If radius = 10 then (slant height)^2 = 12^2 + 10^2 = 244

slant height = 15.6204993518

surface area = PI * 10 * 15.62 = 376.99

376.99 / 188.4955 = 2

So, if radius is doubled, surface area is doubled.

Source: http://www.1728.org/volcone.htm

 

Step-by-step explanation: