Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • 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

Answers (1)

best_answer

Solution: We know that the opposite angles of a cyclic quadrilateral are supplementry

i.e A+C=pi ,B+D=pi \ \Rightarrow A=pi -C,B=pi -D\ \Rightarrow cosA=cos(pi -C)=-cosC\ \Rightarrow cosB=cos(pi -D)=-cosD\\ herefore cosA+cosB+cosC+cosD=-cosC-cosD+cosC+cosD=0

Posted by

Deependra Verma

View full answer

Similar Questions

Latest Question