The ancient Egyptian architects and craftsmen used the triangular level and plumb level to ensure that all building surfaces were smooth and perfectly aligned. From the tomb of Sennedjem came a set of these tools, including a royal cubit rod, a triangle level, two plumb levels, two right squares, and several other pieces. Sennedjem may have used these instruments to help build and decorate the tombs of Seti I and Ramesses II in the Valley of the Kings, as well as his own splendid burial place.

This triangle level is constructed of two diagonal pieces of wood joined at right angle, with a short horizontal piece running between these two. The plumb bob in the shape of a heart is suspended by a string from the top of the right angle, when the level is placed on a flat surface, the string of the plumb would fall exactly in the middle of the marks incised in the center of the horizontal piece. If the surface were not properly aligned, the plumb would then indicate the necessary corrections. The inscription that runs around the triangle asks the god Ptah and Re-Horakhty-Atum-Hemiunu for burial and benefits in the afterlife for the ba of Sennedjem. (The Egyptian Museum, Cairo)