From the ground, it seems that the Great Pyramid like every other pyramid has four sides but that is not true. The aerial view of the Great Pyramid of Giza shows that it has 8 sides as can be seen in the picture if observed carefully. Some researchers believe that this was done to keep the stones from shifting.
Then there are others who believe that the eight sides were created due to erosion and that the intended sides were actually 4. It is difficult to believe this theory as the indention on every side is precise, can the wind erode the pyramid with such precision?