Giza Plateau Mapping Project (GPMP) directed by Egyptologist Dr. Mark Lehnar achieved digital modeling of the monument of Queen Khentkawess, as known as the fourth pyramid in Giza. As members of GPMP, the authors report how this digital modeling and volume computation of it were done. First, the monument of Queen Khentkawess was scanned by laser radars with 5[mm] mesh accuracy in average. Some parts of wall of the monument on which hieroglyphs appear were scanned separately with a very high-accuracy (0.1[mm] mesh) laser scanner. Second, these scanned raw data were combined, aligned, and integrated into complete 3-D geometry model on a computer. Finally, computation of volumes of the monument was done from the geometry data of the monument, so that archaeologists could use for investigating relationship among the monument and Great Pyramids, Sphinx, and other temples around Giza Plateau. For this purpose the authors have developed a novel approach for computing volume from laser-scanned set of points (point cloud).