My Math Forum

My Math Forum (http://mymathforum.com/math-forums.php)
-   Geometry (http://mymathforum.com/geometry/)
-   -   [ASK] Two Cones (http://mymathforum.com/geometry/344516-ask-two-cones.html)

Monox D. I-Fly July 4th, 2018 11:18 PM

[ASK] Two Cones
 
Azis wants to make two cones using cartons. The surface area of the first cone is twice the second. The side length of the first cone is also twice the second. Determine the ratio of those cones' radius!

s1 = 2s2
L1 = 2L2
πr1(r1 + s1) = 2πr2(r2 + s2)
r1(r1 + 2s2) = 2r2(r2 + s2)

I was stuck with quadratic equations...

Maschke July 5th, 2018 01:41 AM

Quote:

Originally Posted by Monox D. I-Fly (Post 596222)
Thanks to Denis McField who keeps calling me "Mr. Fly" ...

Are you related to Rufus T. Firefly?

Monox D. I-Fly July 5th, 2018 04:48 PM

Quote:

Originally Posted by Maschke (Post 596228)
Are you related to Rufus T. Firefly?

I prefer D. Waterfly, though.

skipjack July 5th, 2018 09:59 PM

Quote:

Originally Posted by Monox D. I-Fly (Post 596222)
I was stuck with quadratic equations...

It would seem that the surface area is intended to exclude the area of the base.

Monox D. I-Fly July 5th, 2018 10:04 PM

Quote:

Originally Posted by skipjack (Post 596269)
It would seem that the surface area is intended to exclude the area of the base.

But in my language it said "luas permukaan", and it strictly include the base area. Otherwise they would use the phrase "luas selimut" (side area) instead.

skipjack July 6th, 2018 12:15 AM

According to Google's translator, "luas permukaan" means "surface area" (as distinct from "total surface area"). Although a more specific phrase is available, it's possible that the need for it was overlooked.


All times are GMT -8. The time now is 03:40 AM.

Copyright © 2019 My Math Forum. All rights reserved.