This document defines and describes various geometric shapes including points, lines, angles, polygons, polyhedra, circles and spheres. It provides definitions for common geometric terms like line segments, rays, parallel and intersecting lines, acute, obtuse and right angles. It also defines types of triangles, quadrilaterals, regular and irregular polygons as well as three-dimensional shapes such as prisms, pyramids, cones, cylinders, cubes and spheres.

1. Point
a location in space
. .A B
.C

2. Line segment
a straight path joining two
points
A
Bendpoint
endpoint

3. Ray
a straight path
with a starting point that
keeps going in one direction
A B
endpoint

4. Line
a straight path that keeps
going in both directions
A
B

5. Parallel
Lines, rays, segments
that never meet

6. Intersecting
point of intersection
Lines, rays, segments
that meet

7. Perpendicular
right angle
Lines, rays, segments
that meet at right angles

8. Angle
formed by 2 rays or
segments that have the
same endpoint
vertex

9. Right angle
an angle that is 90º

10. Acute angle
an angle that is less than 90º

11. Obtuse angle
an angle that is between
90º and 180º

12. Straight angle
an angle that is 180º

13. Reflex angle
an angle that is between
180º and 360º

14. Triangle
a polygon with 3 sides

15. Scalene Triangle
a triangle with all sides of
different lengths

16. Isoceles Triangle
a triangle
with two sides of same length

17. Equilateral Triangle
a triangle
with all sides of equal length

18. Right Triangle
a triangle
with one right angle

19. Obtuse Triangle
a triangle
with one obtuse angle

20. Acute Triangle
a triangle
with all acute angles

21. Quadrilateral
a polygon
with 4 sides

22. Trapezoid
a quadrilateral
with 1 pair of parallel sides

23. Parallelogram
a quadrilateral
with 2 pairs of parallel sides

24. Rhombus
a quadrilateral
with all sides equal length

25. Rectangle
a parallelogram
with 4 right angles

26. Square
a rectangle
with all sides equal

27. Kite
a quadrilateral with 2 pairs
of adjacent equal sides

28. Pentagon
a polygon with 5 sides
Regular pentagon Irregular pentagon

29. Hexagon
Regular hexagon Irregular hexagon
a polygon with 6 sides

30. Heptagon
a polygon with 7 sides
Regular heptagon Irregular heptagon

31. Octagon
a polygon with 8 sides
Regular octagon Irregular octagon

32. Nonagon
a polygon with 9 sides
Regular nonagon Irregular nonagon

33. Decagon
a polygon with 10 sides
Regular decagon Irregular decagon

34. Undecagon
a polygon with 11 sides
Regular hendecagon Irregular hendecagon

35. Dodecagon
a polygon with 12 sides
Regular dodecagon Irregular dodecagon

36. Circle
a curved line that forms a
closed path on a flat surface

37. Polygon
a closed, 2-dimensional
figure made up of line
segments joined end to end

38. Congruent
exactly the same shape
and size
A
B
C
D

39. Symmetrical
having the same size and
shape on either side of a line

40. Regular Polygon
a polygon
with all sides of equal length

41. Irregular Polygon
a polygon
with sides of different lengths

42. Convex Polygon
a polygon with all vertices
pushed outward

43. Concave Polygon
a polygon with at least one
vertex pushed in

44. Polyhedron
a closed 3-dimensional
figure whose surfaces are
made up of polygons

45. Sphere
a 3D shape
with a single curved surface

46. Cone
a 3D shape
with a circular base,
a curved surface, and one vertex

47. Cylinder
a 3D shape
with 2 congruent circular bases
connected by a curved surface

48. Cube
a polyhedron
with 6 square faces

49. Pyramid
a polyhedron
that has a base and triangular
faces meeting at a point (vertex)
Triangular
pyramid
Square
pyramid
Rectangular
pyramid
Pentagonal
pyramid
Hexagonal
pyramid

50. Prism
Triangular
prism
Square
prism
Rectangular
prism
Pentagonal
prism
Hexagonal
prism
a polyhedron
that has two identical bases
and all flat sides