Class 11 Book Solution from S N Dey in Properties of Triangles Question No: (11)3.16
প্রমাণ করো
\({{cos \ A} \over a}+{a \over bc} = {cos \ B \over b} + {b \over ca }= {cos \ C \over c} + {c \over ab}\)

প্রমাণ করো
\({{cos \ A} \over a}+{a \over bc} = {cos \ B \over b} + {b \over ca }= {cos \ C \over c} + {c \over ab}\)