Illustration to show that if an angle is bisected, and if a line drawn through the vertex perpendicular…

Illustration to show that the bisectors of two supplementary adjacent angles are perpendicular to each…

Illustration to show that the bisector of one of two vertical angles bisects the other.

Illustration to show that the bisector of two pairs of vertical angles formed by two intersecting lines…

Illustration of a dihedral angle bisected by a plane. "Every point in a plane which bisects a dihedral…

Illustration to show that the bisector of the vertical angle of an isosceles triangle bisects the base,…

Illustration to show that if through any point in the bisector of an angle a line is drawn parallel…

Illustration of a circle with diameter and chord drawn. A diameter perpendicular to a chord bisects…

Illustration of the construction used to bisect a given angle.

Illustration of the construction used to bisect a given line.

Illustration of the construction used to escribe circles with centres (centers) called ex-centres of…

Illustration of half of an ellipse. "If through a point P of an ellipse a line is drawn bisecting the…

Illustration used to prove "The line joining the mid-points of two sides of a triangle is parallel to…

Illustration of a parallelogram with diagonals drawn to show they bisect each other.

Illustration used to prove "The line bisecting one side of a triangle and parallel to another side bisects…

Illustration to show that the bisector of an exterior angle of an isosceles triangle, formed by producing…

Illustration of a triangle showing that when a line parallel to the base of a triangle bisects one side,…

Illustration to show that if one of the legs of an isosceles triangle is produced through the vertex…

Illustration to show that if the lines joining the middle points of the sides of a triangle divide the…

Illustration to show that the perpendicular bisector of the base of an isosceles triangle passes through…