If `A,B,C,D` are the angles of a quadrilateral then ` cos""((A+B)/(2))+ cos ""((C+D)/(2))`=

If A,B,C,D are the angles of a cyclic quadrilateral then cos A + cos B+ cos C + cos D=

If A,B,C,D are the angles of a quadrilateral, prove that "cos"1/2(A+B)+"cos"1/2(C+D)=0 .

If A, B, C, D are the angles of a quadrilateral, then show that (i) tan((A+B)/(4) ) = cot((C+D)/(4)) (ii) cos((A+B)/(2))+cos ((C+D)/(2))=0

If A,B,C,D are the successive angles of a cyclic quadrilateral, then- (i) cos((A+C)/2) + cos((B + D)/2) =

MA.B.C.D are the angles of a cyclic quadrilateral then cos 'fr cos B+cos C-cos D=

If A,B,C,D are angles of a cyclic quadrilateral,prove that cos A+cos B+cos C+cos D=0

If A,B,C,D be the angles of a quadrilateral , what is the value of (sin(A+B))/(sin (C+D)) +(cos(C+D))/(cos (A+B))

If A,B,C,D are the angles of a cyclic quadrilateral and cos A+cos B= K(cos C + cos D), then the value of K is

If A ,B ,C ,D are angles of a cyclic quadrilateral, then prove that cos A+cos B+cos C+cos D=0

If A ,B ,C ,D are angles of a cyclic quadrilateral, then prove that cos A+cos B+cos C+cos D=0