Geometry vocabulary review

3. Geometry: a branch of mathematics that
measures and compares
.
points, lines, angles, surfaces, and solids

4. What are:
Points?
Lines?
Angles?
Surfaces?
Solids?

5. The Basics

6. Point:
a single, exact location in space
A point is represented with dot
and label with a letter.
This is how we represent Point A
A .

7. Line:
A straight path that is made of
endless points in both directions
A line is represented by connecting two
labeled points with an arrow on each end.
Add a second labeled point (B)
A
. .
B
This is how we represent Line AB

8. Line Segment:
Part of a line that extends from
one point to another point
A line segment is represented by
connecting two labeled points
A
. .
B
This is how we represent Line AB

9. Parallel lines or line segments:
A pair of lines on the same plane that are the
same exact distance apart and never intersect
(meet)
A___________________B
C___________________D
Line segment AB and line segment CD are the
same distance apart. They will never intersect

10. Ray:
Part of a line, having only one point
A
This is ray A, written as A

11. Angles

12. Angle:
Two rays that have the same
point of origin or vertex
Ray AB and ray AC form angle BAC
C
A B

13. Angle:
There are three types of angles,
Acute, Obtuse, and Right angles.
Acute angles
Measure: between
0 and 89 degrees
Obtuse angles
Measure: between 91
And 179 degrees
Right Angles
Measure: 90 degrees

14. Intersecting lines:
lines that cross at a point

15. Perpendicular lines:
Lines that intersect at right angles
The red and black lines below intersect at a right angle

16. Polygons

17. Polygons
A closed figure made of line segments

18. Regular Polygons
A polygon with all sides the same length
and all angles the same measure.

19. Triangles

20. Triangles:
3 sided polygons
Can be grouped by their angles
Acute triangle
Right triangles Obtuse triangles

21. Triangles:
Can be grouped by their sides
Scalene:
no sides are equal
Isosceles:
two sides are equal
Equilateral:
all sides are equal

22. Quadrilaterals

23. Quadrilaterals:
Four sided polygons
Square
Parallelograms
Rectangle
Rhombus Trapezoid

24. Other
Polygons

25. Pentagons:
Five sided polygons

26. Hexagons:
Six sided polygons

27. Heptagons:
Seven sided polygons

28. Octagon:
Eight sided polygons

29. Nonagon:
Nine sided polygons

30. Decagon:
Ten sided polygons

31. Characteristics
of Polygons

32. Comparing polygons:
Congruent figures: Shapes are
the same size, have the same
angles, and are the same
shape.

33. Comparing polygons:
Congruent figures: Shapes are the same
size, have the same angles, and are the
same shape.

34. Comparing polygons:
Similar figures: Shapes that are
the same shape but not
necessarily the same size.

35. Comparing polygons:
Similar figures: Shapes that are the same
shape but not necessarily the same size.

36. Symmetry

37. Symmetric Figures:
A shape that can be folded in half
(along the line of symmetry)
So that the two halves line up exactly.
Fold along the dotted line

38. Symmetric Figures:
A shape that can be folded in half
(along the line of symmetry)
So that the two halves line up exactly.
Other examples of symmetric figures

39. Circles

40. Circles:
• Circumference: the distance around a
circle(perimeter)
• Diameter: a line that goes through the
center of a circle
• Chord: a straight line joining two points on
the circumference of a circle
• Radius: the distance from the center to any
point on the circumference of a circle.

41. Circles:
• Circumference: the distance around a
circle(perimeter)

42. Circles:
• Diameter: a line that goes through the
center of a circle

43. Circles:
Chord: a straight line joining two points on
the circumference of a circle

44. Circles:
Radius: the distance from the center to any
point on the circumference of a circle.

45. Solids

46. Space Figures: (Solids)
A figure that has volume,
three dimensions.
Faces: flat surfaces of solids
Edges: lines where two faces meet
Vertices: the corners or points of a
solid.

47. Space Figures: (Solids)
A figure that has volume, three dimensions.
Face Edge
Vertices

48. Space Figures: (Solids)
A figure that has volume, three dimensions.

49. Perimeter
and
Area

50. Perimeter and Area:
Measuring polygons
Perimeter
Distance around a shape.
The sum of the lengths of
all sides.
Area
Square units inside a
shape

51. GPonterio PowerPoint