The Fibonacci sequence is a series where each term from the third one onward equals the sum of the two preceding terms. A common sequence is 0, 1, 1, 2, 3, 5, 8… It was introduced by the Italian mathematician Fibonacci in 1202 and is famous because of the rabbit reproduction problem. It's also called the 'rabbit sequence' or the 'golden ratio sequence'.
"Quantitative" in math refers to quantities that can be assigned numerical values and measured; they can be expressed with specific numbers (with or without units) and used in mathematical operations.
A 20-sided polygon is a closed shape with 20 sides and 20 vertices, and the sum of its interior angles is 3240 degrees.
Qualitative data in math and statistics refers to non-numerical data that can't be used for arithmetic operations and is only meant to represent categories, attributes, or characteristics.
A degree is a unit used in geometry to measure the size of an angle, symbolized as °. A full circle is divided into 360 equal parts, and each part is defined as 1 degree.
Units of measurement are standards for measuring the size of things. The internationally used system is the International System of Units, while the commonly used system in China is the traditional Chinese system. In ancient times, it was called 'du liang heng'.
It refers to a situation where a shape or object has a one-to-one correspondence in size, shape, and arrangement relative to a point, line, or plane. Simply put, it's the regular repetition of similar parts of an object. This concept isn't just used in math and geometry; it's also widely found in physics, philosophy, and art and design. For example, the wings of a butterfly or the structure of a human face are typical examples of symmetrical forms.
Symmetry order (also called symmetry number) refers to the minimum number of times an object or system coincides with itself under operations like rotation, translation, or interval changes. It's usually denoted as n, corresponding to n-fold symmetry.
In geometry: if you move a 3D shape relative to a certain plane and it can coincide with itself, that plane is called a plane of symmetry.