Geometry

1. Geometry Points, Lines, and Shapes!

2. Plane • plane A flat surface that stretches into infinity.

3. Point • point A location in a plane or in space, having no dimensions.

4. Line Segment • line segment Two points on a line, and all the points between those two points.

5. Line • line A straight set of points that extends into infinity in both directions.

6. Ray • ray part of a line, with one endpoint, and extending to infinity in one direction.

7. Intersecting Lines • intersecting lines Lines that have one and only one point in common.

8. Parallel Lines • parallel linesTwo lines are parallel if they are in the same plane and never intersect.

9. Perpendicular Lines • perpendicular linesTwo lines are perpendicular if the angle between them is 90 degrees.

10. Angle • angleThe union of two rays with a common endpoint, called the vertex.

11. Acute Angle • acute angleA positive angle measuring less than 90 degrees.

12. Right Angle • right angleAn angle whose measure is 90 degrees.

13. Obtuse Angle • obtuse angleAn angle whose measure is greater than 90 degrees.

14. Straight Angle • straight angle An angle that measures 180 degrees.

15. Polygon • polygon A closed plane figure made up of several line segments that are joined together.

16. Triangle • triangle A three-sided polygon. • Triangles can be classified according to the measures of their angles and their sides.

17. Acute Triangle • acute triangleA triangle each of whose angles measures less than 90 degrees.

18. Right Triangle • right triangle A triangle that contains a right angle.

19. Obtuse Triangle • obtuse triangle A triangle with an obtuse angle.

20. Scalene Triangle • scalene triangleA triangle with no congruent (exactly the same size and shape) sides.

21. Isosceles Triangle • isosceles triangleA triangle with two congruent (exactly the same size and shape) sides.

22. Equilateral Triangle • equilateral triangleA triangle with all sides that are congruent (exactly the same size and shape).

23. Circle • circle The set of points in a plane that are a fixed distance from a given point, called the center.

24. Circle • circle The set of points in a plane that are a fixed distance from a given point, called the center.

25. Quadrilateral • quadrilateral Any four-sided figure is called a quadrilateral.

26. Parallelogram • parallelogram A quadrilateral with opposite sides parallel.

27. Rectangle • rectangle A parallelogram with four 90-degree (right) angles.

28. Square • square A parallelogram with four congruent (equal) sides and four 90 degree (right) angles.

29. Rhombus • rhombus A parallelogram with four congruent (equal) sides. • Opposite angles are congruent.

30. Trapezoid • trapezoid A quadrilateral that has exactly one pair of parallel sides. • The parallel sides are called bases. • The non-parallel sides are called legs. • If the legs have the same length, then the trapezoid is an isosceles trapezoid. Isosceles Trapezoid Isosceles Trapezoid

31. Kite • kite A quadrilateral that is shaped like a diamond. Sometimes people like to fly them!  • It has two distinct pairs of adjacent (side-by-side) congruent sides.

32. Cylinder • cylindera solid figure that has two parallel bases that are congruent circles

33. Cone • conea solid figure that has a flat, circular base and one vertex

34. Cube • cubea solid figure with six congruent square faces

35. Square Pyramid • Square Pyramida solid figure with a square base and with four triangular faces that have a common point

36. Rectangular Prism • Rectangular Prisma solid figure in which all six faces are rectangles.

37. Rotation (turn) • Rotation (turn)a movement of a figure to a new position by turning it around a vertex

38. Reflection (flip) • Reflection (flip)a movement of a figure to a new position by flipping it over a line

39. Translation (slide) • Translation (slide)a movement of a figure to a new position along a straight line