FIRST TERM
BASIC GEOMETRY CONCEPTS AND DEFINITIONS:
Geometry: It is an area wichs studies elements and operations on/in the plane such as points, lines or shapes.
Point: A point is a place or location where two lines intersect.
Line: A one-dimensional object formed by infite points. It has no endpoints.
Ray: A line which begins at a particular point.
Endpoint: An Endpoint is a point at which a line or ray ends or starts.
Midpoint: It is the point in halfway between two end endpoints.
Line segment: It is a line with two endpoint.
Straight line: A line whose points follow the same direction.
Plane: It is a two-dimensional Surface, can be defined by two paralel lines, two intersecting lines or one point and a straight line.
Lenght: Measurement of something from end to end
Mediatrix: It is the line that goes throught the middle of the segment
Bisector: It is the line that goes throught the middle of an angle of 90º
GEOMETRY DRAWING AND SUPPLIES CONCEPTS AND DEFINITIONS:
FreeHand: Drawn by hand without guiding instruments.
Line/Technical drawing: It is a drawing made with the help of supplies.
Compass: It is a tool for drawing circles and arcs.
Set squares: They are two special rulers with a triangle shape. One is called the 45º square and the other the 30/60º square.
Eraser: It is an item to delete something in the black board
Ruler: It is an instrument to do straight lines.
Protactor: It is an item to measure or draw angles on a paper
Maker: It is a pen for having a wrinting point made from pressed fibres.
IMPORTANT DEFINITIONS ABOUT ANGLES AND LINES
Parallels:
They are lines wich never intersect themselves, so all their points are equidistant.
Perpendicular: They are lines which meet forming four right angles.
Oblique / Skew: They are lines which are not parallels neither perpendicular.
Angle: It is a figure formed by two rays (sides of the angle) sharing a common endpoint (vertex).
Complementary angles: They are couples of angleswhich sum is 90º
Suplementary angles: They are couple of angles which sum is 180º
Adyacent angles:They are angles that share one side and the vertex
Angle bisetor: It is the line segment or ray which divides an angle into two equal parts.
Right: A right angle has 90 degrees.
Obtuse: A obtuse angle has more than 90 degrees.
Acute: An acute angle is the one that has less than 90 degrees.
Flat: a flat angle has 180 degrees.
IMPORTANT DEFINITIONS ABOUT CIRCLES
Circle: A set of points at the same distance (equidistant) to a point called center.
Circumference: It is the full length of a circle. The complete distance around a circle.
Center. It is the point equidistant to any of the points on a circle.
Radius: It is the length of a line segment from the center to its perimeter (plural Radii from latin or common english radiuses).
Diameter: A line segment that passes through the center and conects two points of a circle. Its length is double than the radius.
Chord: A line segment which conects points of the circle not through the center.
Arc: Segment of a circle. Whatch out!!!! ARCH is for architecture.
Tangent. Element (straight or curve lines) which touch a circle in one point.
Outer: When an element (line or curve) doesn't touch the circunference, or another element.
Inner: When an element (line or curve) is fittted inside the circumference, or another element, being tangent or not.
Concentric circles: They are circles with diferent radius but place in the plane sharing the center.
SECOND TERM
DEFINITIONS ABOUT POLYGONS
Start Polygon: It is a particular polygon case with a start shapes create out of linking together non consecutive vertice of a regular polygon.
Inscribe Polygon: They are polygons place inside circle so all the vertices of the polygon are placed on the circle.
Circumscribed: They are polygon surrounding a circle begin it sides tangent to the circle inside.
Classification:
- Convex Polygon: Any line draw through the polygon meets its boundary exactly twice. As a consequence all its interior angles are less than 180º equivalently any line segment with endpoints on the boundary passes throught only interior points between two endpoints.
- Concave Polygon: A line may be found which meets its boundary more than twice. Equivalently there exists a line between two boundary points that passes outside the polygon. There is an interiorangle greater than 180º
Equiangular: All their corner, angles or vertices are equal.
Equilateral: All edges or sides are of the same length.
Regular: All their vertices, angles and sides are equal.
Irregular: Show different angles and length for their sides.
Number of sides:
Triangle. 3 sides
Square. 4 sides
Pentagon. 5 sides
Hexagon. 6 sides
Heptagon. 7 sides
Octogon. 8 sides
Eneagon. 9 sides
Decagon. 10 Sides
Dodecagon. 12 sides
Polygons Parts
Sides or edges: Each of the line segments that form a polygon.
Vertex: A point in which two sides or edges meet.
Diagonal: It is a segment line that connects non consecutive vertices.
Perimeter: The path around a polygon, the addition of all its sides.
Center: It is a point equidistant from all the vertices
Aphothem: It is a line segment from the centre of a regular polygon to the midpoint of one of its sides
DEFINITIONS AND CLASSIFICATIONS ABOUT TRIANGLES
Triangle: Is a flat figure with 3 sides and 3 angles
Classification:
1.- According to the sides:
Equilateral Triangle: It has 3 sides and 3 angles both equals.
Isoscelis Triangle: It has 2 sides equal and 2 angles equal too.
Scalene Triangle: It has 3 sides diferents.
2.-According to the angles:
Right Triangle: It has 1 angle of 90 º
Acute Triangle: It has 3 angles < 90º
Obtuse Triangle: It has 1 angle > 90º
THE QUADRILATERAL
They are polygons with 4 sides and 4 vertices.
Classification
Parallelograms:
Square: 4 sides and 4 right angles.
Rectangle: 2 pairs of equal sides and 4 right angles
Rhombus: 4 equal sides and 2 pairs of equal angles.
Rhomboid: 2 pair of equal sides and 2 pair of equal angles.
Non parallelograms:
Trapezium:
Right Trapezium: It is a trapezium which has a right angle
Isosceles Trapezium: It is a trapezium which has 2 equal sides and 2 pairs of equal angles
Scalene Trapezium: It is a trapezium which has different sides and different vertices
Trapezoids or Irregual Quadrilaterals:
No sides are parallel and have no equal sides.
STAR POLYGONS
The star polygons are getted joining constantly and no consecutively the vertices of the regular polygons. According to the number of vertices the star polygon has, we can obtain noone, one or several stars.
There are star polygons that are called false stars because they are formed by several polygons.
Types of star :
Pentagon star: 1 step
Hexagon star: 1 step
Heptagon star: 2 steps
Octogon star: 2 steps
Dodecagon star: 4 steps
THE SYMMETRY
It is a quality of some shapes wich some of their parts are reflections of the others.
Reflection Symmetry: It is a shape quality wich it is formed by 2 halves facing each other with an axis or fold line between, as if both sides were in a mirror.
Symmetry Axis: It is a line wich divides a shape into 2 symmetric halves. Every element of the shape is a reflection of the other side and at the same distance from the axis. Symmetric points are on perpendicular line to it.
Central Symmetry: It is the reflection of an objet thought a point called The Symmetry Center.
Geometric Symmetry: It is a kind of symmetry wich follows accurately the geometric symmetric rules.
Apparent Symmetry: It is the quality of shapes or objets wich show an obvious symmetry but not every point or element follows accuratelly the geometry symmetry rules.
BASIC ELEMENTS OF VISUAL REPRESENTATION
The dot: It is the smallest, most simple element part expression. Its first target is to indicate position since it doesn't follow any direction. It may have different qualities such as size, shape, and colour.
The dot threedimensional capacity: Wheb the size, shape and colour are changed, the dots can create visual sentations of special deepness and volumen.
The dot expresive capacity: The point has a unlimited capacity to represent images and to express ideas and emotions. To do so, visual effects are used.
Optical mix: When colour are mixed with the help of distance. Point isn't mixed on the palette or on the painting. The optical mis was used first by the pointillists.
SOME VOCABULARY ABOUT LINES
Line: It can be defined as a dot in movement. It has position and direction in the space and one of its principal funtion consists on making the shapes outlines.
Zig-zag or broken lines: They are formed by several fragments of straight lines with different directions.
Curly lines: They hold more curves than wavy lines and show loops.
Scribble: Chaotic or meaningless line that are trace ramdomly, usually in first stages of childhood or to fill in some area with a particular texture.
DEFINITIONS ABOUT THE PLANE OR FLAT SHAPE
Plane: Also called shape in visual arts. It could be spot or a brushtroke. It is a two-dimensional surface; height and width but not depth. It has position and direction on the space.
The plane three-dimensional capacity: One of the main goals of the plane consists on creating volumen when several flat shapes get together in different directions.
Flat organic shapes: They follow natural principles and can take countless appearences.
Flat geometric shapes: They follow mathemathical principles. In visual arts are thee main basic geometric shapes: circles, squares and triangles.
