ClipArt ETC
"Two straight lines that are parallel to a third are parallel to each other."

Parallel Lines

"Two straight lines that are parallel to a third are parallel to each other."

Illustration showing the intersection of a plane with an octagonal prism.

Plane Intersecting Octagonal Prism

Illustration showing the intersection of a plane with an octagonal prism.

Diagram of a cone intersected by plane J to form a parabola. Also pictured is a circle formed by the intersection of plane K with the cone. "Every point of a parabola is equidistant from the focus and the directrix."

Cone Intersected by a Plane to Form a Parabola

Diagram of a cone intersected by plane J to form a parabola. Also pictured is a circle formed by the…

Diagram showing how to construct a parabola when given the directrix (d), the focus (F) and the eccentricity (m).

Construction of a Parabola

Diagram showing how to construct a parabola when given the directrix (d), the focus (F) and the eccentricity…

A pusher aeroplane plan illustrating the proper ribbing and wiring for the plane. The wires are used to adjust the wings during flight. Pusher aeroplane propeller is located behind the cockpit.

Front View Pusher Aeroplane Plan

A pusher aeroplane plan illustrating the proper ribbing and wiring for the plane. The wires are used…

A propeller airplane plan illustrating the proper location of the skeleton and placement of the wires controlling the adjustable wings.

Propeller Aeroplane Side Plan

A propeller airplane plan illustrating the proper location of the skeleton and placement of the wires…

A top view plan of a propeller aeroplane, or airplane. The plan shows the proper ribs and skeleton for the wings and back side of the plane.

Propeller Aeroplane Top Plan

A top view plan of a propeller aeroplane, or airplane. The plan shows the proper ribs and skeleton for…

A side view plan of a propeller aeroplane for two people. The plan illustrates the the proper location of the wires to support the the wings on the plane.

Propeller Aeroplane Top Plan

A side view plan of a propeller aeroplane for two people. The plan illustrates the the proper location…

A plan for pusher aeroplane, or airplanes. The propeller of the pusher plane is located behind the cockpit to "push" the plane while flying. The plan illustrates the proper skeleton and wires to control the adjustable wings.

Pusher Aeroplane Plan

A plan for pusher aeroplane, or airplanes. The propeller of the pusher plane is located behind the cockpit…

To determine the angle between two planes.

Angle of Two Planes

To determine the angle between two planes.

Illustration of a plane determined by 2 intersecting lines

Plane Determined by 2 Intersecting Lines

Illustration of a plane determined by 2 intersecting lines

"If a straight line is perpendicular to each of two straight lines at their point of intersection it is perpendicular to the plane of those lines."

Line Perpendicular To Plane

"If a straight line is perpendicular to each of two straight lines at their point of intersection it…

Illustration of a straight line projected upon a plane.

Line Projected Upon Plane

Illustration of a straight line projected upon a plane.

"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."

"The locus of a point in space equidistant from the extremities of a straight line is the plane perpendicular to this line at its middle point."

Locus Point to a Plane

"The locus of a point in space equidistant from the extremities of a straight line is the plane perpendicular…

Oblique lines drawn from a point to a plane.

Oblique Lines Drawn to a Plane

Oblique lines drawn from a point to a plane.

Illustration of a plane determined by 2 parallel lines

Plane Determined by 2 Parallel Lines

Illustration of a plane determined by 2 parallel lines

If a straight line is perpendicular to each of two other straight lines in a plane at their point of intersection, it is perpendicular to the plane of the two lines.

Line Perpendicular to Plane

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

Straight line AB is perpendicular to the lines in plane MN at point B.

Line Perpendicular to Plane

Straight line AB is perpendicular to the lines in plane MN at point B.

Straight line AB is perpendicular to the lines in plane MN at point B. "If from the foot of a perpendicular to a plane a straight line is drawn at right angles to any line in the plane, the line drawn from its intersection with the line in the plane to any point of the perpendicular is perpendicular to the line of the plane."

Line Perpendicular to Plane

Straight line AB is perpendicular to the lines in plane MN at point B. "If from the foot of a perpendicular…

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.

Illustration of a plane rotated about a straight line.

Plane Rotated About a Straight Line

Illustration of a plane rotated about a straight line.

The intersection of two planes is a straight line.

Intersecting Planes

The intersection of two planes is a straight line.

The intersection of two planes is a straight line.

Intersecting Planes

The intersection of two planes is a straight line.

The intersection of two planes is a straight line.

Intersecting Planes

The intersection of two planes is a straight line.

The intersection of two planes is a straight line.

Intersecting Planes

The intersection of two planes is a straight line.

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…

Illustration of two parallel planes. "Two planes perpendicular to the same straight line are parallel."

Parallel Planes

Illustration of two parallel planes. "Two planes perpendicular to the same straight line are parallel."

Two parallel planes cut by a third plane.

Parallel Planes

Two parallel planes cut by a third plane.

Two parallel planes perpendicular to a line (AB). "A straight line perpendicular to one of two parallel planes is perpendicular to the other also."

Parallel Planes

Two parallel planes perpendicular to a line (AB). "A straight line perpendicular to one of two parallel…

Three parallel planes cut by two lines.

Parallel Planes Cut By 2 Lines

Three parallel planes cut by two lines.

Illustration of a prism - a polyhedron of which two faces are equal polygons in parallel planes, and the other faces are parallelograms.

Prism

Illustration of a prism - a polyhedron of which two faces are equal polygons in parallel planes, and…

Illustration of the intersection of a prism and a plane.

Intersection of a Prism and a Plane

Illustration of the intersection of a prism and a plane.

"A series of planes as S—S are passed perpendicular to the axis of revolution, cutting out the circles shown on the end view. The points at which these circles cut the 'flat' are projected back as points on the curve." —French, 1911

Intersection of Surface of Revolution and Plane

"A series of planes as S—S are passed perpendicular to the axis of revolution, cutting out the…

A propeller airplane with rudder, elevator, and ailerons. The rudder stabilizes the plane vertical, and elevator adjusts the pressure exerted by the horizontal stabilizer for a downward force.

Airplane Rudder and Elevator

A propeller airplane with rudder, elevator, and ailerons. The rudder stabilizes the plane vertical,…

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is tangent to the sphere."

Sphere With Tangent Plane

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is…

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is tangent to the sphere."

Sphere With Tangent Plane

Illustration of a sphere with a tangent plane. "A plane perpendicular to a radius at its extremity is…

Illustration of the intersection of a square pyramid and a plane.

Intersection of Square Pyramid and a Plane

Illustration of the intersection of a square pyramid and a plane.

Illustration of the intersection of a square pyramid and a plane.

Intersection of Square Pyramid and a Plane

Illustration of the intersection of a square pyramid and a plane.

Inclined plane forming right triangle showing the velocity of a body sliding a distance,s, down a smooth horizontal plane.

Inclined Plane Forming Right Triangle

Inclined plane forming right triangle showing the velocity of a body sliding a distance,s, down a smooth…

Illustration of the intersection of a triangular pyramid and a plane.

Intersection of Triangular Pyramid and a Plane

Illustration of the intersection of a triangular pyramid and a plane.