# 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

Points are considered fundamental objects in Euclidean geometry.

## Lines

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

 Lines Definition Piture Perpendicular lines Two lines intecsect at a point to form an angle 90o ${\overline {AB}}\perp {\overline {CD}}$  Parallel lines Two lines will not intersect with each other ${\overline {AB}}{//}{\overline {CD}}$ Vector Line with its direction ${\vec {AB}}$  ## Angles

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 $\angle$ . Angles are measured in degrees (o) or radians (Rad).

Example angle 90 degree is π radian

$\angle A=90^{o}={\frac {\pi }{2}}Rad$

## Geometric figures

### Polygons

Polygons are shapes of <$n$  sides and include:

 Polygon Definition Types Polygon Figure of n sides Triangle 3 sided polygon Isosceles triangle | Right triangle | Equilateral Triangle Quadrilateral 4 sided polygon Rectangle | Square | Parallelogram | Rhombus | Trapezoid