 4 Parallel Lines Cut By 2 Transversals

Illustration used to prove the theorem "If three or more parallel lines intercept equal segments on… Circles With Parallels Intercepting Equal Arcs

Illustration of a circle with parallels intercepting equal arcs on a circumference. Line Divided Into Equal Parts

Illustration used to show how to divide a given straight line into any number of equal parts. Planes Perpendicular To A Line

"Two planes perpendicular to the same straight line are parallel." Parallel Lines

"Two straight lines perpendicular to the same plane are parallel." Parallel Lines

"Two straight lines that are parallel to a third are parallel to each other." Line Joining Midpoints on a Triangle

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

An illustration showing the construction used to erect a parallel line. "With C as a center, draw the… Lines Perpendicular To A Plane

"If one of two parallels is perpendicular to a plane, the other is also." 3 Intersecting Planes

Illustration of three intersecting planes. "The intersections of two parallel planes by a third plane… 3 Intersecting Planes

Illustration of three intersecting planes. "The straight line perpendicular to one of two parallel lanes… 3 Parallel Planes

"If two straight lines are cut by three parallel planes, the corresponding segments are proportional." Angles In Parallel Planes

"If two angles not in the same plane have their sides respectively parallel and lying in the same direction,… Parallel Planes

"If two intersecting lines are each parallel to a given plane, the plane of these lines is parallel… Line Bisecting Side of a Triangle

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

Illustration used to prove the theorem "The line bisecting one of the non parallel sides of a trapezoid…