If A,B,C,D are the four angles taken in order of a cyclic quadrilateral prove that, `tan A +tan B+ tan C +tan 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, prove that cos A+cos B+cos C+cos D=0.

If A, B, C, D be the angles of a quadrilateral, prove that : (tanA+tanB+tanC+tanD)/(cotA+cotB+cotC+cotD) = tan A tan B tan C tan D

If A, B, C, D be the angles of a quadrilateral, prove that : (tanA+tanB+tanC+tanD)/(cotA+cotB+cotC+cotD) = tan A tan B tan C tan D

Given that A = B +C. prove that tan A - tan B - tan C = tan A tan B tan C.

If A,B,C,D are the angles of quadrilateral, then find (sum tan A)/(sum cot A).

If A +B = 225 ^(@), prove that tan A + tan B =1- tan A tan B

If A , B , C , D are the angles of a quadrilateral, then (tanA+tanB+tanC+tanD)/(cotA+cotB+cotC+cotD) is equal to: (a) tanAtanBtanCtanD (b) cotAcotBcotCcotD (c) tan^2A+tan^2B+tan^2C+tan^2D (d) sumtanAtanBtanC

If A ,\ B ,\ C are the interior angles of a triangle A B C , prove that tan(B+C)/2=cotA/2

If A B C D is a cyclic quadrilateral in which A D || B C . Prove that /_B=/_C