pics

3-star vertical alignment on the meridian due south, of Betelgeuse, Alnitak, and Theta 2 Orionis, the middle star in the 'Sword' of Orion c. 2560 BC Giza, Egypt:

The upper diagram shows the north faces of the 'Bent' pyramid aligned with Betelgeuse, the uppermost star, and with Alnitak, the middle star in the Orion vertical alignment c.2630 BC

The lower diagram shows the north face of the 'Red' pyramid aligned with Alnitak due south c.2590 BC