BASIC GEOMETRY CONCEPTS AND DEFINITIONS
Geometry It is an area of knowledge which studies only elements and operation on the plane such as points
Greek Is earch metry is measurement
Point In geometry a point can be defined as place or location where 2 lines intersect. A point hasn´t dimensions no height and no width.
Line A one dimension object formed of infinite points.It hasn´t end and continues on forever in a plane
Ray A line which behinds a to particular point called the earth point and extends end lessly in one Direction
Mindpoint Is the point that is half way between the endpoints of the line segment
Line segment It's a line with the endpoints
Lenght Measurement of something from end to end
Geometry Drawing and subjects concepts and definitions
Freehand Draw by without guiding instructions
Line/Techimal Drawing It's a drawing used for architector or enginiering plans
Compass It's a tool for drawing circles and also for measuring distances between points, consisting of 2 arms linked by a hinge
Protactor An instrument for measuring of drawing angles in a paper, usually a flat semicircular transparent plastic sheet graduated in degrees
Set Square and Triangles They're 2 special rulers
Eraser Is a tool that sirves to quit points, lines, etc....
Ruler Is a tool that sirves to mide lenghts
Circle Set of ponts at the some distance (equidistant) to a point called center
Circunference It's the full lenght of a circle. The complete distance around a circle
Center It's the point equidistant to any of the points an a circle
Radius This is the lenght of a line segment from the center and conects 2 points of o circle
Chord A line segment which conects 2 points of the circle but don't pass to the center
Anc Line segment of a circle
Paralells They're lines which never intersect themselves so all their points are equidestent
Perpendicular They're lines which meet farming 4 right angles
Oblique They're lines which aren't paralells neither perpendicular
Angle It's a figure formed by 2 rays sharing a common endpoint
Complementary They're angles which sum is 90 º
Suplementary They're couples of angles which sum is 180 º
Adjacents They're angles that share one ride and the vertex
Right Obtuse
Acute Flat
Complete Zero
The angle bisector It's an angle that is divide into 2 parts equals
Star Palygon It's a particular palygan are without a star shope, created aut of linking together non consecutive vertex of a regular polygon.
Inscribed polygons They're polygons place inside circles so all vertex of the polygon are ploced on the circle.
Circunscribed They're polygons sarraunding a circle being it's sides tangent to the circle inside.
Equiangular All the corners, angles and vertex are equal.
Equilateral All edges or sides are of the same lenght
Regular All their vertex, angles and sides are equal
Irregular Shaw different angles and lenght for their sides.
Triangle It's a flot figure with 3 sides and three angles.
Equilateral 3 sides
Isosceles 2 sides equal
Scalene 3 sides no equal
Right 1 angle sum 90º
Acute 3 angle equal
Obtuse 1 angle < 90º
Quadrilaterals They are polygons winth 4 sides and four vertices
Parallelograms They're quadrilaterals with 2 pairs of paralellos apparide equal sides and 2 pairs of apparide equal angles their diagonal bisect eoch other
Square 4 sides = 4 angles
Rectangle 4 sides = 2 by 2
Rhambus 4 sides = 4 angles = 2 by 2
Rhamboid 4 sides = 2 by 2 , 4 angles = 2 by 2
Trapezium Only one pair of sides are paralles
Right trapezium 1 angle = 90º
Isosceles Tropezium 2 sides paralles, 2 sides =
Scalen Trapezium 2 sides paralles, 4 equals
Trapezoid 4 sides =/ non paralles
Triangle It's a flot figure with 3 sides and three angles.
Equilateral 3 sides
Isosceles 2 sides equal
Scalene 3 sides no equal
Right 1 angle sum 90º
Acute 3 angle equal
Obtuse 1 angle < 90º
Quadrilaterals They are polygons winth 4 sides and four vertices
Parallelograms They're quadrilaterals with 2 pairs of paralellos apparide equal sides and 2 pairs of apparide equal angles their diagonal bisect eoch other
Square 4 sides = 4 angles
Rectangle 4 sides = 2 by 2
Rhambus 4 sides = 4 angles = 2 by 2
Rhamboid 4 sides = 2 by 2 , 4 angles = 2 by 2
Trapezium Only one pair of sides are paralles
Right trapezium 1 angle = 90º
Isosceles Tropezium 2 sides paralles, 2 sides =
Scalen Trapezium 2 sides paralles, 4 equals
Trapezoid 4 sides =/ non paralles
SYMMETRY
It´s a quality of same shapes which some of their parts are reflectione of others.
Reflection symmetry It´s a shape´s quality which is formed by 2 halves facing each other with on axis or fold line in between as if both sides were mirror images of each other
Symmetry axis It´s a line which divides a shape into 2 symmetric halves. Symmetric points are on perpendicular line to it.
Central Symmetric It´s the reflection of an object through a point called the symmetry center. Symmetric par of points are collinear with the center.