The Pyramids at Giza are geometrically related

The axis that joins two midpoints of G1 to two midpoints of G3 is at 45 degrees to North-South and in the exact direction of Iunu (Heliopolis). It's length is exactly 2000 cubits. These figures can be confirmed using Petrie's data.

The location of G2 in the red square between the pyramids is half way between the G1 and G3 using the mid points on the axis.

This is confirmed using Petrie's data and comes to 790.3 cubits from each pyramid.

This is enough to demonstrate a geometric relationship.