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

2 parallel horizontal lines with arrows on both ends to show that they extend indefinitely.

2 parallel horizontal lines with arrows on both ends to show that they extend indefinitely. The top…

2 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

2 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

2 parallel vertical lines with arrows on both ends to show that they extend indefinitely.

2 intersecting lines, one of which is vertical and one of which is horizontal. The intersection forms…

3 parallel horizontal lines with arrows on both ends to show that they extend indefinitely.

3 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

3 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

3 parallel vertical lines with arrows on both ends to show that they extend indefinitely.

Illustration of line segment AB, which is made up of line segments AC and CB. C is considered the midpoint…

4 parallel horizontal lines with arrows on both ends to show that they extend indefinitely.

4 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

4 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

4 parallel vertical lines with arrows on both ends to show that they extend indefinitely.

5 parallel horizontal lines with arrows on both ends to show that they extend indefinitely.

5 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

5 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

5 parallel vertical lines with arrows on both ends to show that they extend indefinitely.

6 parallel horizontal lines with arrows on both ends to show that they extend indefinitely.

6 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

6 parallel lines with arrows on both ends to show that they extend indefinitely. The lines are slanting…

6 parallel vertical lines with arrows on both ends to show that they extend indefinitely.

"That point in which a right line drawn from the eye parallel to another given right line cuts the picture…

Alphabet of lines are lines needed to cover the lines with labeling symbols within the diagram.

Illustration used to show how to "draw a straight line through any given point on a given straight line…

Illustration used to show how to construct a bisector of an angle when the sides intersect within the…

Illustration used to show how to construct a bisector of an angle when the sides no not intersect within…

Illustration of a dihedral angle bisected by a plane. "Every point in a plane which bisects a dihedral…

Illustration of a convex polyhedral angle. "The sum of the face angles of any convex polyhedral angle…

Illustration used to show "The two perpendiculars to the sides of an angle from any point in its bisector…