CIRCLE_E  Three Circle Problem (EASY)
Given 3 distinct circles with positive integer radius R1, R2, and R3, and arranged like in the picture below:
Now, your task is to compute radius of small circle that can be created like yellow circle in the picture above. All circles in the picture above tangent each other.
Input
The first line in the input data, there is an integer T(0 < T ≤ 10^{3}) denoting number of test cases, than T lines follow.
For each lines, there are three integer R1, R2, and R3, (0 < {R1,R2,R3} < 10^{9}) denoting radius of each circle like in the picture above.
Output
For each test case, output radius of small circle that can be made, like in the picture above. Any output with absolute error less than 10^{6} is accepted.
Example
Input: 3 1 1 1 10 10 10 23 46 69 Output: 0.154701 1.547005 6.000000
You can see my submission history and time record for this problem: here
hide comments
mishra_sharad:
20160814 21:23:10
don't be confused by integer inputs mentioned in problem....use double otherwise WA is waiting for u...long long int costed me one WA... 

ritik_agr:
20160708 09:11:51
use of formula only 

vineetpratik:
20160706 11:43:38
the inner soddy circle 

shubham9466:
20160313 17:19:10
for c/c++: Use double for taking radius input


street_funker:
20160223 18:52:50
use double


rishabh_1997:
20160215 19:45:52
too easy if u know the formula...


try2catch:
20160203 02:28:13
50th! ^_~'


ragwave:
20160102 13:17:04
use setiosflags(ios::fixed) to avoid large answer in exponential form!! 

hmp:
20151218 06:22:08
equate 3 smaller triangle's area to a larger triangle area and get required radius. 

kiner_shah:
20151105 10:03:23
Soddy circles! Got it! AC! 
Added by:  Tjandra Satria Gunawan 
Date:  20130405 
Time limit:  1s 
Source limit:  10000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 
Resource:  Own Problem 