ClipArt ETC
2 parallel horizontal line segments.

Segments, 2 Parallel Line

2 parallel horizontal line segments.

2 slanted parallel line segments.

Segments, 2 Parallel Line

2 slanted parallel line segments.

2 slanted parallel line segments.

Segments, 2 Parallel Line

2 slanted parallel line segments.

3 parallel horizontal line segments.

Segments, 3 Parallel Line

3 parallel horizontal line segments.

4 parallel horizontal line segments.

Segments, 4 Parallel Line

4 parallel horizontal line segments.

4 parallel lines cut by a 5th line known as the transversal.

Transversal, 4 Parallel Lines Cut By A

4 parallel lines cut by a 5th line known as the transversal.

5 parallel horizontal line segments.

Segments, 5 Parallel Line

5 parallel horizontal line segments.

6 parallel horizontal line segments.

Segments, 6 Parallel Line

6 parallel horizontal line segments.

6 slanted parallel line segments.

Segments, 6 Parallel Line

6 slanted parallel line segments.

6 slanted parallel line segments.

Segments, 6 Parallel Line

6 slanted parallel line segments.

Illustration to show that if through any point in the bisector of an angle a line is drawn parallel to either of the sides of the angle, the triangle thus formed is isosceles.

Angle Bisector Drawn Parallel to A Side

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

Illustration showing 2 intersecting circles with a line drawn through each point of intersection terminated by the circumferences. The chords joining the ends of theses lines are parallel.

Two Intersecting Circles With Lines

Illustration showing 2 intersecting circles with a line drawn through each point of intersection terminated…

Illustration showing 2 circles with that touch each other and two lines drawn through the point of contact terminated by the circumference. The chords joining the ends of theses lines are parallel.

Tangent Circles With Chords

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

"If a cone be cut by a plane, parallel to the base, so as to form two parts, the lower part is called the frustum of the cone." — Hallock, 1905

Cone

"If a cone be cut by a plane, parallel to the base, so as to form two parts, the lower part is called…

"When all of the positive plates are connected on one side, and all of the negative plates are connected on the other side, as shown, the cells are said to be joined in parallel, or in multiple arc." -Avery 1895

Parallel Connection

"When all of the positive plates are connected on one side, and all of the negative plates are connected…

Illustration used to construct a circle that shall pass through a given point and cut chords of a given length from two parallels.

Construction of a Circle Through a Given Point that Cuts Chords of Given Lengths From Parallels

Illustration used to construct a circle that shall pass through a given point and cut chords of a given…

Illustration showing that tangents drawn at the ends of any diameter are parallel to each other.

Parallel Tangents to an Ellipse

Illustration showing that tangents drawn at the ends of any diameter are parallel to each other.

Each section is an ellipse. The surface is generated by an ellipse moving parallel to itself along two ellipses as directices.

Ellipsoid

Each section is an ellipse. The surface is generated by an ellipse moving parallel to itself along two…

A flashcard featuring an illustration of a Parallel Lines

Flashcard of a Parallel Lines

A flashcard featuring an illustration of a Parallel Lines

A flashcard featuring an illustration of a Parallelogram

Flashcard of a Parallelogram

A flashcard featuring an illustration of a Parallelogram

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts parallel to the base." —Hallock 1905

Inclined Plane with the Force Acting Parallel to the Base

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts…

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts parallel to the plane." —Hallock 1905

Inclined Plane with the Force Acting Parallel to the Plane

"An inclined plane is a slope, or flat surface, making an angle with a horizontal line...the force acts…

The parallel fret band is a pattern that is parallel in perspective that was found in a Roman mosaic pavement.

Parallel Fret Band

The parallel fret band is a pattern that is parallel in perspective that was found in a Roman mosaic…

"In railway engineering, the running together of parallel tracks into the space occupied by one, by crossing the two inner rails so as to bring each side by side with the opposite outer rail." -Whitney, 1911

Gauntlet Track

"In railway engineering, the running together of parallel tracks into the space occupied by one, by…

"Hand-vices are used in the manner implied by their name, without being attached to a bench like the foregoing." — Encyclopedia Britannica, 1893

Hand-Vice

"Hand-vices are used in the manner implied by their name, without being attached to a bench like the…

Illustration showing a line that remains parallel to a given line, and touches at one end a given circumference.

Straight Line Moving to Two circles

Illustration showing a line that remains parallel to a given line, and touches at one end a given circumference.

Illustration showing a line that moves so that its ends constantly touch two fixed lines which are perpendicular to each other. Locus of the midpoint.

Circle Made by Ends of a Line Touching Two Fixed Lines Perpendicular to Each Other

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

Projections of a line parallel to a plane.

Projections of a Line

Projections of a line parallel to a plane.

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

Parallel Lines

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 to the other also.

Parallel Lines

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

Illustration of two parallel lines with equal segments between them. Two parallel lines are everywhere equally distant.

Parallel Lines With Equal Segments Between

Illustration of two parallel lines with equal segments between them. Two parallel lines are everywhere…

Projections of a lines parallel to ground line.

Projections of a Lines

Projections of a lines parallel to ground line.

Illustration showing that when three or more parallel lines intercept equal parts on one transversal, they intercept equal parts on every transversal.

Parallel Lines Cut By A Transversal

Illustration showing that when three or more parallel lines intercept equal parts on one transversal,…

Illustration showing that if two parallel lines are cut by a transversal, then the alternate interior angles are equal.

Parallel Lines Cut By A Transversal

Illustration showing that if two parallel lines are cut by a transversal, then the alternate interior…

Illustration showing that when two straight lines in the same plane are cut by a transversal, if the alternate interior angles are equal, the two straight lines are parallel.

Parallel Lines Cut By A Transversal

Illustration showing that when two straight lines in the same plane are cut by a transversal, if the…

Illustration showing that when two parallel lines are cut by a transversal, the exterior-interior angles are equal.

Parallel Lines Cut By A Transversal

Illustration showing that when two parallel lines are cut by a transversal, the exterior-interior angles…

Illustration showing that when two parallel lines are cut by a transversal, the two interior angles on the same side of the transversal are supplementary.

Parallel Lines Cut By A Transversal

Illustration showing that when two parallel lines are cut by a transversal, the two interior angles…

"a is the sphere, placed in half-holes on the axis bb, so that when its principal axis is parallel to the axis the telescope it gives only one image of the object. In a direction perpendicular to that axis it must be so placed that when it is moved by rotation of the axis bb the separation of the images shall be parallel to that motion. The angle of rotation is measured on the grduated circle C. The angle between the objects measured is = r sin 20, where r is a constant to be determined for each magnifying power employed." —The Encyclopedia Britannica, 1903

Micrometer

"a is the sphere, placed in half-holes on the axis bb, so that when its principal axis is parallel to…

"a is the sphere, placed in half-holes on the axis bb, so that when its principal axis is parallel to the axis the telescope it gives only one image of the object. In a direction perpendicular to that axis it must be so placed that when it is moved by rotation of the axis bb the separation of the images shall be parallel to that motion. The angle of rotation is measured on the grduated circle C. The angle between the objects measured is = r sin 20, where r is a constant to be determined for each magnifying power employed." —The Encyclopedia Britannica, 1903

Micrometer

"a is the sphere, placed in half-holes on the axis bb, so that when its principal axis is parallel to…

"Thus, were the rays falling on the mirror parallel, the focus would be at a' but in consequence of their previous convergency, they are brought together at a less distance than the principal focus." -Comstock 1850

Convergent Rays in a Concave Mirror

"Thus, were the rays falling on the mirror parallel, the focus would be at a' but in consequence of…

"The incident rays, a and b, being parallel before they reach the reflectors, are thrown off at unequal angles in respect to each other, for b fallson the mirror more obliquely than a, and consequently is thrown off more obliquely in a contraty direction, therefore, then angles of reflection being equal to those of incidence, the two rays meet at c." -Comstock 1850

Plane Inclined Mirrors

"The incident rays, a and b, being parallel before they reach the reflectors, are thrown off at unequal…

Draftsman's second method for drawing a parabola

Parabola Second Method

Draftsman's second method for drawing a parabola

Illustration showing that if two tangents RP and RQ are drawn from a point R to a parabola, the line drawn through R parallel to the axis bisects the chord of contact.

Tangents to a Parabola

Illustration showing that if two tangents RP and RQ are drawn from a point R to a parabola, the line…

"Diagram of a multiple or parallel connection. When connected in this manner the voltage of the battery is the same as that of a single cell, but the current is equal to the amperage of a single cell multiplied by the number of cells." -Hawkins, 1917

Parallel Connection

"Diagram of a multiple or parallel connection. When connected in this manner the voltage of the battery…

Figure showing battery cells connected in parallel, with all of the positive ends wired together, and all of the negative ends wired together.

Parallel Connection

Figure showing battery cells connected in parallel, with all of the positive ends wired together, and…

Illustration showing two parallel vertical lines cut by a perpendicular line and a transversal. Congruent line segments are marked.

Parallel Lines Cut By a Perpendicular And Transversal

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

"Its mechanism may be understood by the means of the subjoined figure, B represents the end of the beam, which is pulled downward, and pushed upward, by the motion of the piston-rod R P; the motion of B is in the direction of the dotted curve; that of R P is rectilinear." —Comstock, 1850

Parallel Motion

"Its mechanism may be understood by the means of the subjoined figure, B represents the end of the beam,…

To draw a plane through a given point parallel to a given plane.

Parallel Planes

To draw a plane through a given point parallel to a given plane.

"The English parallel vice is little used except for small work." — Encyclopedia Britannica, 1893

Parallel Vice

"The English parallel vice is little used except for small work." — Encyclopedia Britannica, 1893

Diagram used to prove the theorem: "The opposite faces of a parallelopiped are equal and parallel."

Equal and Parallel Opposite Faces of a Parallelopiped

Diagram used to prove the theorem: "The opposite faces of a parallelopiped are equal and parallel."

"A parallelopipedon is a prism whose bases (ends) are parallelograms." —Hallock 1905

Parallelopipedon

"A parallelopipedon is a prism whose bases (ends) are parallelograms." —Hallock 1905

Diagram used to prove the theorem: "The rectangular parallelopipeds which have two dimensions in common are to each other as their third dimension."

Relationship Between 2 Parallelopipeds With Equal Altitudes

Diagram used to prove the theorem: "The rectangular parallelopipeds which have two dimensions in common…

Diagram used to prove the theorem: "The rectangular parallelopipeds are to each other as the product of their three dimensions."

Relationship Between Dimensions of Parallelopipeds

Diagram used to prove the theorem: "The rectangular parallelopipeds are to each other as the product…

"If one of two parallels is perpendicular to a plane, the other is also."

Lines Perpendicular To A Plane

"If one of two parallels is perpendicular to a plane, the other is also."

Illustration of a plane determined by 2 parallel lines

Plane Determined by 2 Parallel Lines

Illustration of a plane determined by 2 parallel lines

Two straight lines, AB and CD, perpendicular to the same plane (MN) are parallel.

Lines Perpendicular to Plane

Two straight lines, AB and CD, perpendicular to the same plane (MN) are parallel.

Two intersecting planes on a third plane. "If two intersecting planes are each perpendicular to a third plane, their intersection is also perpendicular to that plane."

Intersecting Planes

Two intersecting planes on a third plane. "If two intersecting planes are each perpendicular to a third…

Two arrangements of pulley: crossed belt and uncrossed belt. The pulleys are constructed with two circles that have the radii labeled and tangent lines drawn (strings).

Pulley

Two arrangements of pulley: crossed belt and uncrossed belt. The pulleys are constructed with two circles…

"If a pyramid be cut by a plane, parallel to the base, so as to form two parts, the lower part is called the frustum of the pyramid." — Hallock, 1905

Pyramid

"If a pyramid be cut by a plane, parallel to the base, so as to form two parts, the lower part is called…

"From the surface of a plane mirror, parallel rays are reflected parallel; but the convex mirror causes parallel rays falling on its surface to diverge, by reflection." -Comstock 1850

Divergent Rays

"From the surface of a plane mirror, parallel rays are reflected parallel; but the convex mirror causes…