Question
Question: If circum-radius and in-radius of a triangle be 10 and 3 respectively then value of a cot A + b cot ...
If circum-radius and in-radius of a triangle be 10 and 3 respectively then value of a cot A + b cot B + c cot C is equal
to-
A
13
B
26
C
39
D
None of these
Answer
26
Explanation
Solution
We know in ∆ABC = a cot A + b cot B + c cot C
= 2(R + r) = 26