GEOMETRY

Geometry: is a science that studies the shapes, the points and the lines. It comes from the Greek words "geo" and "metry".
Point: is the place where two lines intersect.
Line: is an infinit write of a sucesion of infinit points.
Ray: it´s a line that has beggining and doesn´t have end.
Line segment: it´s a line with two endpoints.
End point: is the point where a ray or a segment line ends or starts.
Freehand: draw without any instruments of drawing.
Compass: it´s an instrument to make circles and arcs and take messures.
Length: measure of something from end to end.




DEFINITIONS ABOUT ANGLES AND LINES
Parallels: lines which never intersect themselves.
Perpendicular: two lines that when intersect, they form four right angles.
Oblique: lines that aren´t perpendiculars and parallels.
Angle: two lines that have a common point (vertex).
Right angle: angle of 90º
Obtuse angle: angle of more than 90º
Acute angle: angle of less than 90º
Flat angle: angle of 180º
Complet angle: angle of 360º
Complementary angles: two angles that form 90º
Suplementary angles: two angles that form 180º

DEFINITIONS ABOUT CIRCLES
Circle: set of points at the same distance to the center
Circumference: it's the full length of a circle. The complete distance a round a circle is the perimeter
Center: point equidistant to any of the points of a circle
Radius: it´s a line from the center and the perimeter
Diameter: line segment that goes from a point of the perimeter to another point, passing for the center of the circle
Chord: line that connects two points of the circle not through the center
Arc: segment of a circle
Arrow: segment that divides an arc in the middle. It´s the center of the chord
Tangent: line that only touch a point of a circle
Outer: element that doesn´t touch the circunference
Inner: element inside the circumference
Concentric circles: circles with different radius but place in the plane s                                                          

  UNIT 2: POLYGONS

POLYGONS

      NUMBER OF SIDES                              TYPES                                  ELEMENTS     
          3 TRIANGLE                                                                                  DIAGONALS

          4 QUADRILATERAL                REGULAR  IRREGULAR               SIDES

          5 PENTAGON                                                                                 ANGLES                                                            6 HEXAGON                                   ALTITUDE

          7 HEPTAGON                                                                                 VERTICES

          8 OCTAGON                       INSCRIBED    GIVEN                         OTHER ITEMS

          9 ENNEAGON                                  THE SIDE    

        10 DECAGON