Sher Mohammad
Last Activity: 11 Years ago
A + B = 180-C
take tan of both sides
(tan A + tan B)/(1-tan A tan B) = - tan C
or tan A + tan B + tan C = tan A tan B tan C
divide both sides Tan A tan B tan C
1/tan B 1/ tan C + 1/tan A 1/ tan C + 1/ tan A 1/tan B = 1
cot B cot C+ cot A cot C + cot A cot B = 1
sher mohammad
b.tech, iit delhi