 ### Perpendiculars To The Sides Of An Angle

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

Illustration of polyhedral angle. "The opening of three or more planes which meet at a common point… ### Straight Angle

An illustration showing a straight angle. When the sides of an angle extend in opposite directions,… ### Trihedral Angle

Trihedral angle. "The sum of any two face angles of a trihedral angle is greater than the third face… An illustration of two angles that are adjacent. They have the same vertex and a common side between…  ### Two Equal Dihedral Angles

Illustration of 2 equal dihedral angles. ### Equal Dihedral Angles

Illustration of 3 equal dihedral angles. "Two dihedral angles have the same ratio as their plane angles." ### Equal Polyhedral Angles

Illustration of two polyhedral angles that are equal. ### Equal trihedral angles

Illustration used to show that two trihedral angles are equal or symmetrical when the three face angles… ### Right Angles With Same Vertex

An illustration showing when one straight line meets another straight line and makes the adjacent angles… ### Angles With Same Vertex

An illustration of angles with the same vertex made up of 4 lines. ### Symmetrical Polyhedral Angles

Illustration of two symmetrical polyhedral angles. ### Vertical Angles

Vertical angles are when two angles have the same vertex, and the sides of the one are prolongations… ### Vertical Dihedral Angles

Illustration of two vertical dihedral angles. ### Approximate Ellipse using Lines

"When the minor axis is at least two-thirds the major, the following method ma be used: Make CF and… ### Distribution of Magnetic Lines, Ring Armature

"Distribution of magnetic lines through a ring armature. Since the lines follow the metal of the ring… ### Barry Bendy

"Formed by lines drawn horizontally, crossed by others drawn diagonally."—Aveling, 1891 ### Paly Bendy

"Produced by lines drawn vertically, by others drawn diagonally, or by a compound of Paly and Bendy."—Aveling,… ### Line, Broken

A zig zag line known as a broken line in mathematics. ### Line, Broken

A zig zag line known as a broken line in mathematics. ### Line, Broken

A zig zag line known as a broken line in mathematics. ### Line, Broken

A zig zag line known as a broken line in mathematics. ### Circle With Diameter, Radius, Segment, Line

Illustration showing a circle with a diameter, radius, lines, triangle, and segment drawn. ### Circle Inscribed in a Right Triangle

Illustration showing the diameter of a circle inscribed in a right triangle is equal to the difference… ### Circle With Inscribed Triangle and Radii

Illustration showing a circle with an inscribed triangle and radii. ### Circle With Various Chords

Illustration showing a circle with various chords drawn. ### Circle With Various Chords

Illustration showing a circle with various chords drawn. ### Circle With Various Chords And Tangents

Illustration showing a circle with various chords and tangents drawn. ### Circle With Various Chords And Tangents

Illustration showing a circle with various chords and tangents drawn. ### Circle With a Right Triangle

Illustration where one leg of a right triangle is the diameter of a circle. The tangent at the point… ### Circle With a Tangent Line and Chord

Illustration showing that from any point in the circumference of a circle, a chord and a tangent are… ### Two Intersecting Circles With Lines

Illustration showing 2 intersecting circles with a line drawn through each point of intersection terminated… ### Two Intersecting Circles With Lines

Illustration showing 2 intersecting circles with a lines drawn that form a triangle. ### Tangent Circles With Chords

Illustration showing 2 circles with that touch each other and two lines drawn through the point of contact… ### Spherical Cone

"If a sector revolves about its bounding radius as an axis, it generates what may be called a spherical… ### Construction of Bisecting a Given Angle

Illustration of the construction used to bisect a given angle. ### Construction of Bisecting a Given Arc

Illustration of the construction used to bisect a given arc. ### Construction of Bisecting a Given Line

Illustration of the construction used to bisect a given line. ### Construction of an Equal Angle Given a Point and a Straight Line

Illustration of the construction used to create an equal angle given a point in a given straight line… ### Construction of Perpendicular Upon a Given Line From an External Point

Illustration to let fall a perpendicular upon a given line from a given external point. ### Construction of Perpendicular From a Given Point on a Straight Line

Illustration of the construction of a perpendicular to a line when given a point O on the straight line. ### Construction of Perpendicular From a Given Point on a Straight Line

Illustration of the construction of a perpendicular to a line when given a point B on the straight line. ### Construction of a Straight Line Divided Into Equal Parts

Illustration of the construction used to divide a straight line into a given number of equal parts. ### Construction of a Straight Line Parallel to a Given Straight Line

Illustration of the construction used to create straight line parallel to a given straight line through… ### Curve Inked with Circle Arcs

"Any noncircular curve may be approximated by tangent circle arcs, selecting a center by trial, drawing… ### Line, Curved

A curved line with endpoints. This illustration resembles a parabola. ### Projection of a Curved Line

Illustration of a projection of a curved line. ### Drawing Irregular Isometric Curves of Solid

The illustration of an irregular curves for solid. The isometric projection of the curve can be drawn… ### Angle of Depression

Illustration showing an angle of depression from a horizontal line to a line of sight. ### Construction Of Dividing A Line

Illustration used to show how to divide a given straight line into required number of equal parts.