Four-Point Geometry

Section 1.3 Four-Point Geometry

Figure 1.3.1. A model for the four-point geometry.

A geometric model for incidence geometry that feels more geometric is shown in Figure 1.3.1. This model is known as the four-point affine plane. An alternate version is shown in Figure 1.3.2. Are these models the same? What about the model shown in Figure 1.3.3?

Activity 1.3.1. Exploring four-point geometry (and GeoGebra).

Explore these GeoGebra models by selecting and moving various objects.

Figure 1.3.2. Another model for the four-point geometry.

Figure 1.3.3. Yet another model for the four-point geometry.