If I have r as an inradius of a triangle and ra, rb, rc are the three radii of the 3 excircles of that triangle how can I show that:

1/ra+1/rb+1/rc=1/r?

Results 1 to 4 of 4

- March 2nd 2010, 04:39 AM #1

- Joined
- Oct 2009
- Posts
- 5

- March 2nd 2010, 05:24 AM #2

- March 2nd 2010, 08:20 AM #3

- Joined
- Oct 2009
- Posts
- 5

- March 2nd 2010, 09:03 AM #4