Comparison method, two-phase comparison, like to find fault, one by one comparison, external performance such as flatness, image temperament, angular, three-dimensional level, dark color! Size and so on, intrinsic quality, molecular density, material, and its volatility and effectiveness.
1. Chinese interpretation
Similar; Similar. Yi Cohesion: "It is close to heaven and earth, so it does not violate." Xiao Tong's Song of Picking Lotus in the Southern Dynasties: "Gui Yanlan floats with clear water, and the jade on the river is similar."
"Zhong Yiyuan Ming Ji" by Li Yu in Qing Dynasty: "As long as the paintings are somewhat similar, there will be no home. It's enough for me to give you some advice and correct it. " Lao She's fair black and white plum: "In fact, their faces are very white and look alike.
2. Mathematical explanation
If two shapes are the same, but not necessarily equal in size, they are similar. There are two geometric figures f and f', if all their points can establish a one-to-one correspondence, and the ratio of any line segment on figure f to the corresponding line segment on figure f' is constant.
Then f and f' are called similar figures or similar shapes, and the two figures of f and f' are similar, marked as F∽F', and the symbol ""is pronounced similar to. The ratio of corresponding line segments is called their similarity ratio (or similarity coefficient).
3. Determination method
A straight line parallel to one side of a triangle intersects with the other two sides to form a triangle similar to the original triangle. Two angles are equal and two triangles are similar.
If two sides of one triangle are proportional to two sides of another triangle and the included angle is equal, then two triangles are similar (two sides are proportional and the included angle is equal, and two triangles are similar).
If three sides of one triangle are proportional to three sides of another triangle, then two triangles are similar (three sides are proportional and two triangles are similar). If two angles of two triangles are equal (or three angles are equal), then two triangles are similar.