Lesson 1-2 Section 1-4

Postulate

Definition

Example 1

Example 2

Definition

Construction

Postulate

Example 3

Example 4

Example 5

What about the distance?  We used the ruler postulate for finding the distance between two points on a line, but how can we find the distance of a line in a coordinate plane?  Let’s see…..

Definition

Example 6

Example 7

Is there another way?  We have now mastered finding the distance between two points in the coordinate plane. However, there is another way of going about it.  We can use a very famous theorem: The Pythagorean Theorem. Let’s see how we do that….

Definition

Example 8

Example 8 cont.

Example 9

Practice  Try the following problems:  Pg. 32 # 5-15 odd, 12