Geometry (from the Template:Lang-grc; geo- "earth", -metron "measurement") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space. A mathematician who works in the field of geometry is called a geometer.
Points are considered fundamental objects in Euclidean geometry.
By Eucleur axiom, line can be drawn from 2 points . Example through 2 points A and B , we can draw a line AB
Example of lines
Lines of interest
Lines Definition Piture Perpendicular lines Two lines intecsect at a point to form an angle 90o Parallell lines Two lines do not intecsect each other Vector Line with its direction
Two lines intersect at a point to form an angle between 2 lines . Example Line AB intersects line AC to form an angle A between 2 lines . Angle has a symbol . Angle is measured in Degree(o) or Radian (Rad)
Example angle 90 degree is π radian
Acute angle , angle less than 90°
Right angle , angle equals to 90° (1/4 vòng tròn);
Obstuse angle angle greater than 90° and less than 180°
Góc bẹt là góc 180° (1/2 vòng tròn).
Góc phản là góc lớn hơn 180° nhưng nhỏ hơn 360°
Góc đầy là góc bằng 360° (toàn bộ vòng tròn).
Geometry figure is a figure of n sides include
Geometry Figure Definition Types Polygon Figure of n sides Triangle 3 sided polygon of Isosceles triangle | Right triangle | Equilateral Triangle Quadrilateral 4 sided polygon of Rectangle | Square | Parallelogram | Rhombus | Trapezoid