Pythagorean theorem: Pythagorean theorem is one of the most famous geometric theorems, which shows that in a right triangle, the square on the right side is equal to the sum of the squares of the other two sides. This theorem can be traced back to the ancient Greek mathematician Pythagoras.
2. Parallelism Theorem: Parallelism Theorem includes many different theorems, such as the judgment theorem of parallel lines and the property theorem of parallel lines. These theorems describe the relations and properties between parallel lines.
3. The theorem of triangle interior angle sum: The theorem of triangle interior angle sum shows that the sum of three interior angles of a triangle is equal to 180 degrees. This theorem was first put forward by the ancient Greek mathematician Euclid.
4. Calculation of pi: pi is an irrational number, indicating the ratio of the circumference to the diameter of a circle. In ancient times, people approached the value of π through measurement and calculation. Modern mathematics has developed many methods to calculate the more accurate value of π.
5. Fermat's last theorem: Fermat's last theorem is a famous problem in number theory, which shows that when n is greater than 2, the equation X N+Y N = Z N has no positive integer solution. This theorem was first put forward by the French mathematician Fermat, but it was not proved by andrew wiles until 1994.
6. Four-color theorem: Four-color theorem is a famous problem in graph theory, which shows that any plane map can be colored with four colors, making adjacent areas different in color. This theorem was first proposed by Francis Goodrich in 1852 and proved by Kenneth Appel and Wolfgang Harken in 1976.