Fundamental Mathematics/Geometry
Geometry 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[edit | edit source]
Points are considered fundamental objects in Euclidean geometry.
Lines[edit | edit source]
By Euclid's axioms, a line can be drawn from 2 points. Example through 2 points A and B, we can draw the line AB.
- A---------------B
Lines of interest[edit | edit source]
Lines | Definition | Piture | |
Perpendicular lines | Two lines intecsect at a point to form an angle 90^{o} | ||
Parallell lines | Two lines do not intecsect each other | ||
Vector | Line with its direction |
Angles[edit | edit source]
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 . Angles are measured in degrees (^{o}) or radians (Rad). Failed to parse (unknown function "\rad"): {\displaystyle \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).
Geometric figures[edit | edit source]
Polygons[edit | edit source]
Polygons are shapes of < sides and include:
Polygon | 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 |