The circumcentre of the triangle ABC is O . Prove that `angle OBC+angle BAC=90^@`.

O is the circumcentre of the traiangle ABC prove that angleOBC+angle BAC=90^(@)

(i) The circumcentre of the triangle ABC is O, If angle BOC=80^@, then angle BAC=

O is the circumcentre of Delta ABC and OD bot BC . Prove that angle BOD= angle BAC

The circum-centre of a triangle ABC is O. If angle BAC = 85 ^(@) , angle BCA =75^(@) , then angle OAC is of

O is the circumcentre of the triangle ABC and angle BAC = 85^@ , angle BCA = 75^@ , then the value of angle OAC is

(ii) Orthocentre of the triangle ABC is O, If angle BAC=40^@ , then angle BOC=

O is the circumcentre of the triangle ABC. If angle BAC =50^@ , then angleOBC is equal to

(iii) Incentre of the triangle ABC is O, If angle BAC = 40^@ , then angle BOC =