2 lines that are intersected by a third line known as a transversal.

Transversal, 2 Lines Intersected By A

2 lines that are intersected by a third line known as a transversal.

Illustration used to prove the theorem "If three or more parallel lines intercept equal segments on one transversal, they intercept equal segments on any other transversal."

4 Parallel Lines Cut By 2 Transversals

Illustration used to prove the theorem "If three or more parallel lines intercept equal segments on…

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.

The cross-ratio of four points in a line is equal to the cross-ratio of their projections on any other line which lies in the same plane with it.

Cross-Ratio Four Points

The cross-ratio of four points in a line is equal to the cross-ratio of their projections on any other…

Illustration that shows if two parallel lines are cut by three or more transversals that pass through the same point, the corresponding segments are proportional.

Parallel Lines Cut by Transversals

Illustration that shows if two parallel lines are cut by three or more transversals that pass through…

Illustration that shows if two parallel lines are cut by three or more transversals that pass through the same point, the corresponding segments are proportional.

Parallel Lines Cut by Transversals

Illustration that shows if two parallel lines are cut by three or more transversals that pass through…

Illustration showing that a transversal is a straight line that cuts two or more straight lines.

Lines Cut By A Transversal

Illustration showing that a transversal is a straight line that cuts two or more straight lines.

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…

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…

Illustration used to prove the theorem, "If two straight lines are cut by a transversal making a pair of alternate interior angles equal, the lines are parallel."

Parallel Lines Cut By A Transversal Theorem

Illustration used to prove the theorem, "If two straight lines are cut by a transversal making a pair…

Illustration used to prove the theorem, "If two parallel lines are cut by a transversal, the alternate interior angles are equal."

Parallel Lines Cut By A Transversal Theorem

Illustration used to prove the theorem, "If two parallel lines are cut by a transversal, the alternate…

Illustration of two straight lines cut by a transversal. The 8 angles formed are labeled.

2 Lines Cut By A Transversal

Illustration of two straight lines cut by a transversal. The 8 angles formed are labeled.

Illustration of two straight lines, m and n, cut by a transversal t.

2 Lines Cut By A Transversal

Illustration of two straight lines, m and n, cut by a transversal t.

Illustration of two straight lines, AB and CD, cut by a transversal EF.

2 Lines Cut By A Transversal

Illustration of two straight lines, AB and CD, cut by a transversal EF.