2 intersecting lines, one of which is vertical and one of which is horizontal. The intersection forms…

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

Illustration used to show "The two perpendiculars to the sides of an angle from any point in its bisector…

Illustration used to show "The two perpendiculars to the sides of an angle from any point not in its…

An illustration showing when one straight line meets another straight line and makes the adjacent angles…

Angles used to illustrate the sum and difference of two angles and trig identities.

Illustration showing angles 1 and 2 are supplementary and angles ACD and DCB are supplementary. Also,…

Illustration used to show that "A tangent to a circle is perpendicular to the radius drawn to the point…

Illustration of a circle with a tangent drawn - a straight line perpendicular to a radius at its extremity.

Illustration of the construction used to bisect a given line.

Illustration to let fall a perpendicular upon a given line from a given external point.

Illustration of the construction of a perpendicular to a line when given a point O on the straight line.

Illustration of the construction of a perpendicular to a line when given a point B on the straight line.

Coordinate axis with angle XOP equal to theta, Θ, and angle XOQ=180 - Θ. From any point in the terminal…

Angle XOP=Θ and angle XOQ=- Θ. From a point in the terminal side of each a perpendicular line is drawn…

Angle XOP=Θ and angle XOQ=90+Θ. From a point in the terminal side of each a perpendicular line is…

Illustration used to prove the corollary that "Two lines perpendicular respectively to two intersecting…

Illustration used to prove the corollary that "From a point outside a line there exists only one perpendicular…

"The earth shown as it would be if its axis were perpendicular to the plane of the orbit." -Wiswell,…

Illustration of the projection of a hexagonal pyramid that is in a right position.

Illustration modeling the illumination on a surface when the surface is not perpendicular to hte rays…

Illustration of an extension ladder. If ladder is leaned against a building, it will form a right triangle…

Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned…

Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned…

Illustration of a ladder that is not perpendicular to the ground. If it is set on the ground and leaned…

Illustration of a ladder leaning against the side of a building (wall) to form a right triangle .

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a…

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a…

Illustration of a ladder leaning against a palm tree, that is perpendicular to the ground, to form a…

Illustration of 2 ladders leaning against opposite sides of a palm tree to form similar right triangles.…

Illustration of 3 ladders leaning against the side of a building (wall) to form right triangles. The…

Illustration showing a line that moves so that its ends constantly touch two fixed lines which are perpendicular…

Illustration showing that the perpendicular is the shortest line that can be drawn to a straight line…

Illustration showing two straight lines drawn from the same point in a perpendicular to a given line,…

Illustration of two straight lines drawn from a point in a perpendicular to a given line, cutting off…

Illustration showing only one perpendicular can be drawn to a given line from a given external point.

Illustration showing two straight lines in the same plane perpendicular to the same straight line are…

Illustration showing if a straight line is perpendicular to one of two parallel lines, it is perpendicular…

Illustration showing two parallel vertical lines cut by a perpendicular line and a transversal. Congruent…

The correct position when the pen is at the bottom of an extended letter below the line, the pen being,…

A perpendicular line drawn from point P to straight line RS.

Two planes lie perpendicular to one another. A line perpendicular to plane 1 and a line perpendicular…

If a straight line is perpendicular to each of two other straight lines in a plane at their point of…