1. Points, Lines, and Line Segments
A Geometry presentation by Olivia Ingram

2. Points
Points are places on a number line, often identified by a single dot “•” and are named an alphabetical letter. • A • B

3. Lines come in three forms:
Ray
Line
Line Segment • • • •

4. Measuring Points and Line Segments
On a number line, you can easily measure the distance between two points. A B • • 1 2 3 4 5 6 7 8
Two ways to solve:
Count the spaces between the points
Subtract the smallest number from the largest number
4 spaces between points = 4
6 – 2 = 4

5. Measuring Points and Line Segments
You may need to measure line segments whose points lie on both positive and negative numbers, which may throw you for a loop, but is just as simple. A B • • -4 -3 -2 -1 1 2 3 4
When counting, the negative and positive symbols make no difference
Do not solve this by subtraction. Ignoring the negative and positive symbols, add the points together:
= 2
1 + 1 = 2

6. Measuring Points and Line Segments
Once you know how to measure the distance between points on a line segment, measuring more than two points on a line segment should be a piece of cake.

7. Answering Equations
You should write the measurement of the distance between points using letters and symbols. A B • • 1 2 3 4 5 6 7 8
= AB

8. Points, Lines, and Line Segments: Practice Problems• • -4 -3 -2 -1 1 2 3 4 X Y • • 1 2 3 4 5 6 7 8 9 A C • • • -4 -3 -2 -1 1 2 3 4

9. Points, Lines, and Line Segments: Practice Problem Answers
1) AB = 5
2) XY = 2
3) AC = 5