Petrie described Khufu’s Sarcophagus as ”The coffer in the King's Chamber is of the usual form of the earliest Egyptian sarcophagi, an approximately flat–sided box of red granite. It has the usual under–cut groove to hold the edge of a lid along the inside of the N., E., and S. sides; the W. side being cut away as low as the groove for the lid to slide over it; and having three pin–holes cut in it for the pins to fall into out of similar holes in the lid, when the lid was put on…” The Pyramids and Temples of Gizeh, Chapter 7, Inside of Great Pyramid, Coffer, character
These captures were taken from Hitachi-Systems’ video “The Great Pyramid Project （大ピラミッド探査プロジェクト 英語字幕バージョン） [released 19MAY20]. The Hitachi team utilized a JEPICO, high-performance, 100-million pixel camera. These high-resolution images reveal a crispness and the acute straightness of the challenging cut.
Dr. Troglodyte