Introduction to Pythagorean Theorem;

Pythagorean theorem is a basic geometric theorem, which means that the sum of the squares of two right angles of a right triangle is equal to the square of the hypotenuse. In ancient China, right-angled triangles were called Pythagorean Theorem, the smaller right-angled side was a hook, the other longer right-angled side was a chord, and the hypotenuse was a chord, so this theorem was called Pythagorean Theorem, and some people called it quotient height theorem.

There are about 500 ways to prove Pythagorean theorem, and Pythagorean theorem is one of the most proven theorems in mathematics. Pythagorean theorem is one of the important mathematical theorems discovered and proved by human beings in the early days. It is one of the most important tools to solve geometric problems with algebraic ideas, and it is also one of the ties of the combination of numbers and shapes. In China, Shang Gao of the Zhou Dynasty put forward a special case of Pythagorean Theorem "Hook three strands, four chords and five".

Theorem uses:

The third side is solved by knowing the two sides of a right triangle, or the lengths of the three sides of the triangle are known, which proves that the triangle is a right triangle or proves that the two sides of the triangle are vertical. Using Pythagorean Theorem to find the length of line segment is the most basic application of Pythagorean Theorem.

Other mathematical terms:

1, arrangement

Arrangement, generally speaking, m(m≤n) elements are taken from n different elements and arranged in a column in a certain order, which is called the arrangement of taking m elements from n elements. In particular, when m=n, this arrangement is called full arrangement.

2. Solution set

Solution set is a mathematical term, which refers to all solutions of an equation (group) or inequality (group) as a set of elements, and is called the solution set of the equation (group) or inequality (group). There are three ways to express the solution set: enumeration, description and illustration. As an important tool in mathematics, solution set has a wide range of applications in mathematics.

3. Equation

An equation refers to an equation containing unknowns. It is an equation that represents the equal relationship between two mathematical expressions (such as two numbers, functions, quantities and operations), and the value of the unknown quantity that makes the equation hold is called "solution" or "root". The process of finding the solution of the equation is called "solving the equation".

4. Cubic

Cubes are also called cubes. The product of three identical numbers is called the cube of this number. For example, 5×5×5 is called the cube of 5, and it is recorded as 5? .