Introduction to Geometry

1
Introduction to Geometry

• Chapter 1.1

2

• Point
• Is represented by a dot.
• We use capital letters to name points.

3

• Line
• Made up of points and are straight.
• The arrows on the ends show that the lines extend
  infinitely far in both directions.

B
m
A
4

• Segment
• Made up of points and are straight.
• Has a definite beginning and end.

5

• Ray
• Made up of points and are straight.
• Begins at an endpoint and extends infinitely in
  only one direction.

E
B
D
A
C
6

• Angle
• Two rays that have the same endpoint
• The endpoint is called the vertex.

A
C
B
4
7

• Triangle
• A three sided polygon.
• A polygon consisting of 3 noncollinear points
  joined by segments.

8

• Plane
• A flat surface that extends in all directions
  indefinitely.
• It has no thickness.
• 3 noncollinear points determine a plane.

9
A Point A Line A Plane
Point

• Corner of a box.
• Clothesline
• Side of a box
• Parking Lot
• Edge of a box
• Ceiling of a room
• City on a map

Line
Plane
Plane
Line
Plane
Point
10
8. 9. 10. 11. 12. 13. 14.