🗊Презентация Median, bisector and the height of the triangle

Median, bisector and the height of the triangle

Goals lesson Education: Introduction of new concepts heights, medians and bisectors of a triangle. Educational: to educate the ability to listen and hear. Developing: Develop a stable cognitive interest in the study of geometry

Plan lesson Greeting (2min) Organizing time (3min) To explain the new material (15min) Work together with the teacher (15min) Reflection (5min) Give homework (2min) Summarizing time (3min)

The median of the triangle - the segment connecting the top with the middle of the triangle opposite side. In any triangle, you can spend 3 median. All of them intersect at a single point, the center (center of gravity) of the triangle. The median of the triangle - the segment connecting the top with the middle of the triangle opposite side. In any triangle, you can spend 3 median. All of them intersect at a single point, the center (center of gravity) of the triangle. - median   О - center  . 

The properties of the medians of a triangle The properties of the medians of a triangle 1. The median divides the triangle into two triangles of equal area. 2. The medians of a triangle intersect at one point, which divides each of them in the ratio of 2:1, starting from the top. This point is called the center of gravity of the triangle. 3. The whole triangle is divided into six their medians of equal triangles.

The bisector of the triangle - the segment bisector angle of the triangle, connecting the apex of the triangle with the point on the opposite side. Please note that the bisector of the angle - a ray that divides the angle equal to two, and the bisector of the triangle - is cut, part of the beam, limited side of the triangle. The bisector of the triangle - the segment bisector angle of the triangle, connecting the apex of the triangle with the point on the opposite side. Please note that the bisector of the angle - a ray that divides the angle equal to two, and the bisector of the triangle - is cut, part of the beam, limited side of the triangle. - bisector  ,  - bisector  

Each triangle can be carried out three bisectors that intersect at a single point, usually denoted Latin letter I. The point of intersection of the bisectors of the triangle (I) - Center the in circle. Each triangle can be carried out three bisectors that intersect at a single point, usually denoted Latin letter I. The point of intersection of the bisectors of the triangle (I) - Center the in circle.

Properties triangle bisectors Properties triangle bisectors The bisector of angle - a locus of points equidistant from the sides of the angle. Bisector internal angle of a triangle divides the opposite side into segments proportional adjacent sides: x / y = a / b. The point of intersection of the bisectors of the triangle is the center of a circle inscribed in the triangle.

The height of the triangle - the perpendicular drawn from the vertex triangle to the line containing the opposite side.

For example: For example: Two triangles are equal to the angle of 58º and 72º. Find an obtuse angle, which form a triangle of height, coming out of the tops of these angles. Answer give degrees. From the triangle ACH (angle H - straight) find the angle CAH. He is 18º. From the triangle ACK (K - line) find the angle ACK. He is 32º. In a triangle AOC two angles are known. We find the third, that is AOC, the angle which is obtuse angle between the height of the triangle ABC: Answer: 130º

Classwork: p78 №18,19,20,21 Classwork: p78 №18,19,20,21 Homework: p78 №22,23,24