1) When encountering an isosceles triangle, it can be used as the height of the bottom. Using the property of "three lines in one", the thinking mode in congruence transformation is "folding in half".
2) When encountering the midpoint or midline of a triangle, congruent triangles can be constructed as midline or double midline. The thinking mode used in congruence transformation is "rotation". It can also be rotated directly if necessary.
3) When encountering an angular bisector, you can make vertical lines on both sides of a point like an angle on the angular bisector. The thinking mode used is "folding in half" in triangle congruence transformation, and the knowledge points examined are often the property theorem or inverse theorem of angular bisector.
4) Interception and complementation, the specific method is to intercept a line segment on a line segment equal to a specific line segment, or extend a line segment equal to a specific line segment, and then explain it by the related properties of triangle congruence. This method is suitable for proving the sum, difference, multiplication and classification of line segments.
5) Equal area method: Find the area of triangle (or other figure) in different ways to solve the problem between line segments.
6) When encountering the midline of the line segment, the points on the midline connecting the line segment are at the same distance from both ends of the line segment.
7) When encountering a right triangle, make the center line on the hypotenuse of the right triangle.
8) In case of special angle, consider making an equilateral triangle.