If f,g,h are internal bisectoirs of the angles of a triangle ABC, show that `1/f cos, A/2+ 1/g cos, B/2+1/h cos, C/2= 1/a+1/b+1/c`

If f,g,h are the internal bisectors of a /_\ ABC then 1/f cos (A/2)+ 1/g cos (B/2) +1/h cos (C/2)= (A) 1/a+1/b-1/c (B) 1/a-1/b+1/c (C) 1/a+1/b+1/c (D) none of these

In any triangle ABC, show that : 2a cos (B/2) cos (C/2) = (a+b+c) sin (A/2)

If A, B and C are interior angles of a triangle ABC, then show that "sin"((B+C)/2)=cos(A/2) .

if A, B and C are interior angles of a triangle ABC, then show that cos((B+C)/2) = sin (A/2)

if A, B and C are interior angles of a triangle ABC, then show that cos((B+C)/2) = sin (A/2)

If one of the angles A,B,C of a triangle is not acute, show that cos^2A+cos^2B+cos^2C=1

If A ,\ B ,\ C are the angles of a triangle, prove that : cos A+cos B+cos C=1+r/Rdot

In any Delta ABC, show that cos A+ cos B+ cos C = (1+ (r )/(R )).

If cos 3A +cos 3B+cos 3C=1 then one of the angles of the triangle ABC is

If A , Ba n dC are the angels of a triangle, show that |-1+cos B cos C+cos B cos B cos C+cos A-1+cos A cos A-1+cos B-1+cos A-1|=0