Geometric straight line and angle of a plane

Geometric straight line and angle of a plane

Straight Line	(Not defined) a straight line is infinitely extending to two parties, and it has no endpoint.
Ray	The part next to a point in a straight line. Rays have only one endpoint.
Line Segment	The part between two points in a straight line. It has two endpoints.
Vertical Line	If the two straight lines are at the right corner, the two lines are perpendicular to each other. One of them is the vertical line of the other, and their intersection is the vertical foot.
Diagonal lines	If two straight lines do not intersect at a right angle, one of them is the diagonal line of the other.
Distance from point to straight line	The length of the vertical segment from a point outside a straight line to this line is called the distance from a point to a straight line.
Vertical bisector of a line segment	Theorem: the distance between the vertical bisector of a line segment and the two endpoints of the line segment is equal.
Flat line	The two straight lines that do not intersect in the same plane are called parallel lines.
Equality and inference of parallel lines	After a straight line, there is one and only one straight line is parallel to this straight line. Two straight lines parallel to the same line.
Definition of Angle	An image composed of two rays of a common point is called an angle.
Classification of Angle	Zhou Jiao: 360 degrees horizontal angle: 180 degrees right angle: 90 degrees acute angle: 0 degrees <A <90 degrees blunt angle: 90 degrees <A <180 degrees

Ry triangle

Triangle Classification	Sharding	Acute triangle, acute triangle, right triangle
	Split by edge	Equi triangle, equi triangle, not equi triangle
Angular bisector of a triangle	The split line between an angle of a triangle and the opposite side of this angle. The line between the vertex and the intersection of this angle is called the split line of the angle of the triangle.
Midline of a triangle	A line segment connecting a vertex of a triangle is called the midline of a triangle.
Triangle height	The height of a triangle is the vertical line from a vertex to its opposite side.
Middle line of a triangle	A line segment connecting the midpoint of a triangle is called the middle line of a triangle.
Equi-Form
Definition	The two triangles that can completely overlap are called full equi triangles.
Nature	The corresponding edges, corresponding angles, the bisector of the corresponding angles, the height and the midline are equal.
Determination	Any triangle	Right Triangle
	(1) The two sides correspond to the same angle. As SAS	(1) One side is equal to the other.
	(2) The two angles correspond to the same side. As asaa or AAS	(2) The two sides are equal.
	(3) The three sides are equal. Sss	(3) equal oblique and straight corner edges (HL)
Three-angle four-core
Name	Definition	Nature
Inner	The intersection of the three angular bisector of a triangle is called the inner point of a triangle (the center of the inner circle)	(1) The distance from the heart to the three sides of the triangle is equal. (2) A vertex of a triangle shares the angle with the inner link.
External	The intersection of the vertical bisector on the three sides of a triangle is called the outer heart of a triangle. (That is, the center of the outer circle)	(1) The distance from the outer heart to the three vertices of the triangle is equal. (2) the link between the outer heart and the middle point of the Triangle must be vertical. (3) the straight line perpendicular to one side of the Triangle through the outer heart must be evenly divided.
Center of gravity	The intersection of three midline triangles is called the center of gravity of the triangle.	(1) the distance from the center of gravity to the midpoint of each side is 1/3 of the midline. (2) the link between the triangle vertex and the center of gravity must be over the midpoint of the edge.
Focus	The three high points of a triangle are called the center of a triangle.	A vertex of a triangle must be perpendicular to the edges of the vertical center.