Ellipse, shape, Chinese word, pronounced as xíngzhuàng, indicates a form of existence or expression of a specific thing or substance, such as rectangle and square, and also refers to form and appearance. Shape is an abstract concept, and it is a common spatial word that combines perception with mathematical calculation. The shape of matter can be distinguished by angle or curvature.

1, squared. It is a special parallelogram. That is, a group of parallelograms with equal adjacent sides and a right angle is called a square, also known as a regular quadrilateral. A square has all the characteristics of a rectangle and a diamond.

2. Triangle. Triangle is a closed figure composed of three line segments on the same plane but not on the same straight line, which has applications in mathematics and architecture. Ordinary triangles are divided into ordinary triangles (three sides are unequal) and isosceles triangles (isosceles triangles with unequal waist and bottom and isosceles triangles with equal waist and bottom, that is, equilateral triangles); According to the angle, there are right triangle, acute triangle and obtuse triangle, among which acute triangle and obtuse triangle are collectively called oblique triangle.