Pythagorean theorem, formerly known as Pythagorean string theorem. The content is that in a right triangle, the sum of squares of two right-angled sides = the square of the hypotenuse. The formula is: Goufang 10 layer square = chord square.

Since the premise is that there is this theorem in the relationship between three sides in a right triangle, then a triangle that conforms to this theorem is of course a right triangle. The inverse theorem of this theorem holds.

According to the degree of the internal angle of a triangle, it can be divided into three types: right triangle, acute triangle and obtuse triangle.

The definition of a right triangle means that one of the three internal angles of this triangle is a right angle, and such a triangle is a right triangle; An obtuse triangle means that one of the three internal angles of a triangle is obtuse, and this triangle is an obtuse triangle; An acute triangle means that all three angles of the triangle are acute.

The trilateral relationship that conforms to Pythagorean theorem must be a right triangle.

Arithmetic square root: Generally speaking, if the square of a positive number X is equal to A, that is, x2=a, then this positive number X is called the arithmetic square root of A ... In particular, we stipulate that the arithmetic square root of 0 is 0.

Square root: Generally speaking, if the square of a number X is equal to A, that is, x2 = a ... then this number X is called the square root of A, also called the quadratic root. Positive numbers have two square roots; 0 has only one square root, which is 0 itself; Negative numbers have no square root.

A positive number has two square roots, one is the arithmetic square of A, and the other is-,which are opposite. Together, these two square roots can be recorded as positive or negative.

Square root: the operation of finding the square root of a number is called square root, and A is called square root.

Cube root: Generally speaking, if the cube of a number X is equal to A, that is, x3=a, then this number X is called the cube root of A, also called the cube root.

The simplest quadratic root: generally speaking, the number of square roots does not contain denominator, nor does it contain factors or factors that can be completely opened. Such a quadratic root is called the simplest quadratic root.