# 学中文【形状】Shapes in Chinese 学写数学中的汉字 – Learn to Write Chinese Characters in Math

Yuán xíng, sān jiǎo xíng, zhèng fāng xíng, tuǒ yuán xíng, cháng fāng xíng, xīng xíng。

Round, triangle, square, oval, rectangle, star。

A shape is composed of an object or its outer boundary, contour and surface, and has nothing to do with other characteristics of the object (such as color, texture, material composition, etc.). The shape can also be a closed space formed by a side or a curve or a combination of the above two things.

Many simple shapes can be classified. For example, polygons can be divided into triangles, quadrilaterals, pentagons, etc. according to the number of sides. Each category can also be subdivided. For example, triangles can be divided into equilateral triangles, isosceles triangles, acute triangles, obtuse triangles, right triangles, etc., and quadrilaterals can also be divided into rectangles, rhombuses, trapezoids, squares, etc.

Other common shapes are points, straight lines, planes, and conic curves like ellipses, circles, and parabola.

Common three-dimensional shapes are polyhedrons composed of many planes, egg-shaped or spherical ellipsoids, cylinders and cones.

If the shape of an object belongs to a certain category or is close to a certain category, that category can be used to describe its shape. For example, the shape of the manhole cover is a disc, because its shape is similar to a real disc.