Introduction to Basic Geometry

Introduction to basic geometric terms

1. Presented by: Dionelyn Merquita Cruz
Introduction
GEOMETRY:

2. Geometry
Branch of mathematics
concerned with the
properties and relationships
of points, lines, angles,
curves, surfaces, and solids
The visual study of shapes,
sizes, patterns, and positions

3. Basic Geometric Terms

4. An exact location in space
Has no dimension
Point
Read as "point A"
Examples:
tip of a pencil
dot on a map

5. A collection of points along a straight path
that extends continuously in both directions
Has no beginning or end
Illustrated by drawing arrows at each end
Line
Read as "line AB"
Example:
horizon

6. Lines in the same plane that do not
intersect or cross each other
Always the same distance apart
Parallel Lines
Examples:
railway tracks
piano or keyboard keys

7. Two or more lines that meet or
cross each other at a point
Intersecting Lines
Example:
bicycle spokes
intersecting roads

8. Intersecting lines that form a right angle
(90 degrees)
Perpendicular Lines
Examples:
grout lines
between
tiles
the cross

9. A part of a line having two endpoints
Called as "sides" when found in a
shape
Line Segment
Read as "line segment AB"
Examples:
ruler
pencil
stick

10. A part of a line having only one
endpoint
Has a beginning point but no endpoint
Ray
Read as "ray AB"
Examples:
beam of light from a light source
rays of the sun

11. Made up of two rays (called the
"sides") with a same or common
endpoint (called the "vertex")
Measured using a protractor
Angle
Read as "angle ABC" or "angle B"
Examples:
or

12. Kinds of Angles
Acute angles
Right angles
Obtuse angles
Straight angles
Reflex angles
Full rotation
(complete angle)

13. Acute Angle
Measures less than 90
0

14. Right Angle
Measures 90 0

15. Obtuse Angle
Measures greater than 90
0

16. Straight Angle
Measures 180 0

17. Reflex Angle
Measures greater than 180 0

18. Measures 360
Full rotation
Full Angle
0

19. Complementary Angles
Angles that add up to 90 0

20. Supplementary Angles
Angles that add up to 180 0

21. A flat surface that extends indefinitely
in all directions
Plane
Read as "plane JKL" or
"plane KLJ" or "plane LJK"
Can be read as:
"plane MNOP" or
"plane PONM" or
"plane "MPON" (etc.)
Example: surface of a table

22. Two-dimensional (2D) shape
Any set of points on a plane
Includes polygons and any flat
shape (circles, triangles,
quadrilaterals, parallelograms)
PLANE FIGURE

23. a closed curve with
a set of points in
one plane and the
same distance from
a center point
perimeter:
circumference (C)
Circle

24. a flat, two-dimensional (2D) shape with straight sides
that is fully closed (all the sides are joined up). The
sides must be straight.
Polygon
Note:
A circle is not a
polygon.

25. Has 3 sides and
3 angles
The sum of the
inside angles
equals 180
Triangle
0

26. Has 4 sides and
4 angles
Quadrilateral

27. Parallellograms

28. Three-dimensional
(3D) shape
Has depth and takes
up space
SOLID FIGURE

29. Face: the flat surface
(side) of the figure
Edge: where two
faces meet
Vertex or Vertices:
corners
Base: the face on
which the figure rests
SOLID FIGURE

30. Has no faces, edges, or vertices
Completely roundSphere

31. Has one face, but no edges or vertices
Face is in the shape of a circle
Cone

32. has two circular faces but also no edges
or vertices
Cylinder

33. has one base and at least three
triangular faces
Has edges where faces meet each other
or the base, vertices where two faces
meet the base, and a vertex at the top
where all of the triangular faces meet
Is named by the shape of its base.
Pyramid

34. Have a rectangle-shaped or square- shaped
base
Both have four triangular faces, five faces in all
Rectangular and Square Pyramids

35. Has two congruent parallel faces and any number of sides
Can have any number of faces, but at least two of them must be
parallel
The shape of the two parallel faces can be a triangle, square,
rectangle, pentagon, hexagon, or any other kind of polygon
Are named by the shape of their bases.
Prism

36. A prism where all the faces are square
Cube