Prove that the perpendicular bisectors of the sides of a cyclic quadrilateral are concurrent.

Prove that the perpendicular bisectors of the sides of triangle are concurrent.

Show that the perpendicular bisectors of the sides of a triangle are concurrent.

Show that the perpendicular bisectors of the sides of a triangle are concurrent.

Prove analytically : The perpendicular bisector of the sides of a triangle are concurrent.

Prove analytically that the perpendicular bisector of the sides of a triangle ar concurrent.

Prove by vector method that the perpendiculars (altitudes) from the vertices to the sides of a triangle are concurrent.

Prove that the internal bisector of any angle of a cyclic quadrilateral and the external bisector of its opposite angle intersect each other on the circumference of the circle.

Prove that the internal bisectors of the angles of a triangle are concurrent