If A,B,C and D are the angles of cyclic quadrilateral, prove that:
i) `cosA + cosB+cosC+cosD`
ii) `cos(180^(@)-A)+cos(180^(@)+B)+cos(180^(@)+C)-sin(90^(@))`

If A,B,C and D are the angles of cyclic quadrilateral, prove that: i) cosA + cosB+cosC+cosD = 0 ii) cos(180^(@)-A)+cos(180^(@)+B)+cos(180^(@)+C)-sin(90^(@)+D) = 0

If A , B , C ,D are angles of a cyclic quadrilateral , then prove that cosA + cosB+cosC+cosD=0.

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

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 the angles of a cyclic quadrilateral, show that cosA+cosB+cosC+cosD=0

If A, B, C, D be the angles of acyclic quadrilateral, show that : cosA +cosB+cosC+cosD=0 .

If A, B, C, D be the angles of acyclic quadrilateral, show that : cosA +cosB+cosC+cosD=0 .

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