BASIC CONCEP OF ARTS
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 THE 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 sharing the center
DEFINITIONS ABOUT TYPES OF POLYGONS
Star polygons:is a particular polygon case with a star shape, created out of linking together non consecutive
Inscribed polygons: they are polygons place inside circle so all the vertex
Circumscribed polygons: they are polygons sorrounding a circle, being its sides tangent to the circle.
CLASIFICATION OF POLYGONS
Convex polygons: when any line pass for two points of the shape.
Non-convex polygons:when one line through the polygon but it's cut any parts.
Equiangular: all polygons that have angles, vertex and side equals.
Equilateral: all sides of edges are of same length
Regular: all theirs vertices, angles and sides are equal.
Irregular: show different angles and length for their sides.
Polygons parts
Sides: each of line segments that form a polygon.
Vertex: the points in which to sides meet.
Diagonal: segment line that conects non consecutive vertices.
Perimeter: the path around the polygon, the adition of all its sides.
Center: it is apoint equidistance from all the vertices.
THE TRIANGLE
Triangle: it is a flat figure with three sides and three angles.
According to the sides it can be:
Equilateral triangle: is a triangle with sides and vertices equal
Isosceles triangle: is atriangle with two equal sides and angles equal.
Scalen triangle: is a triangle with 3 different sides.
According to the angles it can be:
Right triangle: is a triangle which has one right angle.
Obtuse triangle: is a triangle which has one angle more than 90º
Acute triangle: is a triangle which has three angles less than 90º
QUADRILATERALS
Quadrilaterals: they are polygons with four sides and four angles
