1, when there is an angular bisector, both sides can be perpendicular. The perpendicular bisector of a line segment can connect the two ends of a straight line. The two midpoints of a triangle are connected to form a midline.
2. A triangle has a midline, and the extended midline is equal in length. Proportional, completely similar, often parallel lines. If all the lines are outside the circle, they are tangent to the center of the circle to connect them. If two circles are inscribed inside and outside, they will be tangent through the tangent point.
3. When two circles intersect at two points, they are generally called chords. This is a diameter, this is a semicircle, and I want to make a right angle to connect the lines. Make an equal angle and add a circle to prove that the problem is not that difficult. The auxiliary line is a dotted line, so be careful not to change it when drawing. There is an angular bisector in the picture, which can be perpendicular to both sides.
4, the angle bisector parallel lines, isosceles triangles add up. Angle bisector plus vertical line, try three lines. Perpendicular bisector is a line segment that usually connects the two ends of a straight line.
Brief introduction of junior middle school auxiliary line;
1, the auxiliary line in junior high school refers to the line used to assist in drawing geometric figures in mathematical drawing. They are usually dotted or dotted lines, which help to draw various parts of geometry, such as corners, edges, diagonals, etc.
2. The auxiliary line in junior high school can help students locate the position and size of the graphics more accurately, and make the graphics more standardized and beautiful.
3. Auxiliary lines in junior middle schools can also help students better understand geometric concepts and theorems. For example, when drawing a parallelogram, auxiliary lines can be used to help students understand the concept of diagonal bisection.
4. Pay attention to the use of auxiliary lines in junior high school. Appropriate auxiliary lines should be selected according to the specific situation to avoid using too many or unnecessary auxiliary lines, so as not to affect the beauty and accuracy of the graphics.