All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Shapes > Geometry
Three Circles (Posted on 2004-07-28) Difficulty: 4 of 5
Three circles of radius 6, 7, and 8 are externally tangent to each other. There exists a smaller circle tangent to all three (in the space created between the three original circles).

What is the radius of this smallest circle?

No Solution Yet Submitted by ThoughtProvoker    
Rating: 3.0000 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution Veefessional strikes again! | Comment 5 of 7 |

Well, frankly, the Pythagoras theorem will do it. Give a second, in the process of calculating...

Drawing to scale will not be helpful as the radius of the smallest circle is unknown, as of course, the one we are asked to find!

So, wait, after moving on, it is not the Pythagoras theorem that will solve it, instead, the Cosine-Rule, with the condition that the angle of the point (the centre of the smallest circle) is 360.

So, wait, I am back with the calculation...

UGH! It is futile with the cosine there!

Anyway, I will be back!

  Posted by Vee-Liem Veefessional on 2004-07-30 02:45:59
Please log in:
Remember me:
Sign up! | Forgot password

Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (4)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information