Montessori Geometry
Montessori Geometry: Two Straight Lines Crossed by a Transversal
An introduction to two straight lines (not necessarily parallel) crossed by a transversal. Illustrates interior, exterior, alternate, consecutive, and corresponding angles.
In this presentation, the two straight lines crossed by a transversal are not necessarily parallel. It is an introduction to the terminology and aims to arrive at two conclusions:
- Two straight lines cut by a transversal will form eight angles.
- Two straight lines cut by a transversal form four interior and four exterior angles.
Presentation: Two Straight Lines Crossed by a Transversal
Definitions
A transversal is a line that passes through two lines in the same plane at two distinct points.
Alternate angles are pairs of angles that:
- have distinct vertex points,
- lie on opposite sides of the transversal, and
- are either:
- both interior (called alternate interior angles), or
- both exterior (called alternate exterior angles).
Consecutive interior angles are pairs of angles that:
- have distinct vertex points,
- lie on the same side of the transversal, and
- are both interior.
Corresponding angles are pairs of angles that:
- have distinct vertex points,
- lie on the same side of the transversal, and
- one angle is interior while the other is exterior.
Mastery Quiz: Two Straight Lines Crossed by a Transversal
Name The Angles
