If `A+B+C=180^0`, prove that : `cos^2( A/2) + cos^2( B/2) + cos^2(C/2) = 2+2 sin(A/2) sin( B/2) sin( C/2)`

If A+B+C=180^0 , prove that : cos^2(A/2) + cos^2(B/2) - cos^2(C/2) = 2cos(A/2) cos(B/2) sin( C/2)

If A+B+C=180^0 , prove that : cos^2 (A/2) + cos^2 (B/2) - cos^2 (C/2) = 2cos (A/2) cos (B/2) sin (C/2)

If A+B+C=180^0 , prove that : cos^2, A/2 + cos^2, B/2 - cos^2, C/2 = 2cos, A/2 cos, B/2 sin, C/2

If A+B+C=pi , prove that : sin^2( A/2) + sin^2( B/2) -sin^2( C/2) =1-2 cos( A/2) cos(B/2) sin( C/2)

If A+B+C=180^(@), then prove that cos^(2)(A)/(2)+cos^(2)(B)/(2)+cos^(2)(C)/(2)=2(1+sin(A)/(2)sin(B)/(2)sin(C)/(2))

If A + B + C =180^@ , prove that : cos^2 A- cos^2 B-cos^2 C=2 cos A sin B sinC -1 .

If A + B + C =180^@ , prove that : cos^2 A+ cos^2 B-cos^2 C= 1-2 sin A sin B cos C .

If A+B+ C =pi , then prove that cos ^(2) (A/2)+ cos ^(2) (B/2) +cos ^(2) (C/2)=2(1+sin . (A)/(2) sin. (B)/(2) sin. (C)/(2))

If A + B + C = 180^(@) , prove that cos A + cos B - cos C = -1 + 4 cos (A)/(2) cos"" (B)/(2) sin"" (C )/(2)

If A + B + C = pi then prove that cos A + cos B + cos C = 1 + 4 sin(A/2) .sin(B/2).sin(C/2)