Written records of the history of China date from as early as 1500 BC, from the Shang dynasty (c. 1600â1046 BC). Ancient historical texts such as the Records of the Grand Historian (c. 100 BC) and the Bamboo Annals (296 BC) describe a Xia dynasty (c. 2070â1600 BC) before the Shang, but no writing on a durable medium have survived.
A square is a quadrilateral so it has 360 degrees. A square is a quadrilateral so it has 360 degrees.
Degrees: Circles, Triangles, Rectangles, Squares. Circles. You already know that a circle has 360Â° . Circles can be divided into different sectors: a half circle or semi-circle has 180Â° , a quarter circle has 90Â° , and an eighth of a circle has 45Â° . Circles are covered in more detail elsewhere in the book.