A list of geometry terms, illustrations, and definitions by a sixth grader.

1. Geometry Guide Lines planes points angles

2. Point A dot with a letter

3. Lines A line that goes on for ever f s

4. Line Segment A straight line s m

5. Ray One line that goes on for ever f d

6. Plane A flat end that extends s d a

7. Intersecting Two lines that cross

8. Perpendicular A right angle 90 degrees

9. Parallel Two lines that don't cross

10. Skew Lanes that are not in the same plane

11. Acute A 50 degree angle

12. Obtuse A 180 degree angle

13. Vertex/ Vertice The middle point

14. Right A 90 degree angle

15. Straight A straight angle that equals thats 180 degrees

16. Complementary If the measure is 90 degree 15 75

17. Supplementary If the measure is 180 degrees 100 80

18. Vertical/ Opposite Are opposite two lines interesect r m n p q

19. adjacent Side by side common vertex and ray s t w d f

20. Triangles Obtuse Acute Right Equilateral Isosceles Scalene

21. Obtuse Triangle The greatest angle is the obtuse that equals 180

22. Acute Triangle The greatest angle is an acute angle that equals 180

23. Right Triangle The greatest angle is a right angle that equals 180

24. Equilateral triangle 3 congruent sides

25. Isosceles Triangle At least 2 congruent sides

26. Scalene Triangle No congruent sides

27. Perimeter Add all the sides up 5 5 15 5+5+15=25

28. Sum of Internal Angles The sides and the triangles 4 sides and 2 triangles 2 x 180 = 360

29. Area Time the base and height 10 20 15

30. Quadrilaterals Trapezoid Parallelogram Rectangle Rhombus Square

31. Quadrilateral A box that makes 4 right angles

32. Trapezoid 2 set of parallel line

33. Parallelogram 4 connected sides

34. Rectangle Four right angles

35. Rhombus Four congruent sides

36. Square Congruent sides

37. Area of a Rectangle Times the outside then divided by two 25 10

38. Area of a Square The outside is times then divided 6 8

39. Area of a Parallelogram Times and then divided

40. Area of a Trapezoid The outsides are times then divided 9

41. Circles Chord diameter sector radius

42. Chord Where you draw a line at the top

43. Diameter The middle part of a circle

44. Arc A part of a circle named by two rays with common endpoints. a b

45. Radius The outside of the circle radius

46. Sector A region enclosed by two radii

47. Circumference The distance around a circle 6m.

48. Area of circle The outside of a circle

49. Other Polygons Pentagon hexagon octangon

50. Pentagon It has 5 sides

51. Hexagon All sides are congruent

52. Octogon It has six sides