Question

if a,b,c are interior angles of tra abc, then prove that cosec {a+b/2}= sec {c/2}

Answer 1

Answer:

Answer

Given A,B,C are the interior angles of △ABC

⟹A+B+C=180

∘

⟹A+B=180

∘

−C

LHS=cosec(

2

A+B

)

=cosec(

2

180

∘

−C

)

=cosec(90

∘

−

2

C

)

=sec

2

C

=RHS