According to Saint Louis University, the ancient Egyptians created the square root and most likely used it for architecture, building pyramids and other daily activities that required math. Most of the present-day knowledge of Egyptian math comes from papyri written during the 12th dynasty.
The information comes from two main sources: the Moscow Mathematical Papyrus and the Rhind, or Ahmes, papyrus. The Moscow Papyrus dates back to 1800 B.C.E. and is also known as the Golenischev Mathematical Papyrus, since it was once owned by the Egyptologist Vladimir Golenidenov. The Rhind papyrus is slightly older than the Moscow Mathematical Papyrus and dates back to 1900 B.C.E. Nevertheless, between the two papyri, there are 112 math problems with solutions, often without explanations of how the solutions were computed. For instance, on the Moscow Mathematical Papyrus, the following equation is listed: The square root of 1 + 1/2 + 1/16 = 25/16. This breaks down to 1 + 1/4 (= 5/4). However, no explanation of the solution is provided. The MMP also states that the square root of 16 is four twice, and the square root of 100 is 10. It is believed that the Egyptians had a tablet with the square root of several numbers, which was used as a reference.
Since no explanations of the square root were given, anthropologist have pieced together information about it. For instance, the Egyptian name for the square root was called the kenbet, and it looked like a right angle, similar to the current square root symbol. It is believed that the reason behind the right angle shape was to depict that the square root was similar to the corner of box; it was the “root” of the area because it had equal lengths.