Warm-up

Agenda

Mini-quiz (1-1, 1-2) Homework Review Enrichment 1-3 Section 1-4 Homework

Hand in Definitions

Quiz Time

Quiz 1-1, 1-2

Definitions

A line is one of the basic undefined terms in Geometry. Lines have one dimension – length. They consist of an infinite number of points placed side by side. They are named using lower case script letters or by naming two points on the line with a double arrow above them.

Example

l or AB)************* *

A

B

Study Guide 1-3

Practice 1-3

Practice 1-3

Practice 1-3

Enrichment 1-3

Caution – Answers Ahead

1-3 Enrichment

20 in 45 in

1-3 Enrichment

6 ft

3 ft5 ft

9 ft

Section 1-4 Measuring Segments

AB

C

l

A, B, and C are collinear.

B is between A and C.

Basic Concepts

Postulate – statement that is assumed to be true

Number Line d

d = |-5 – 10|What is the distance from B to E ?

Postulate 1-1Ruler Postulate

Ruler Postulate – The points on any line can be paired with real numbers so that, given any two points P and Q on the line, P corresponds to zero, and Q corresponds to a positive number. P Q

What this really means – you can always measure the distance between two points and that distance will always be a positive number.

Postulate 1-2Segment Addition Postulate

Segment Addition Postulate – If Q is between P and R, then PQ + QR = PR. If PQ + QR = PR, then Q is between P and R.

P Q R

Example

N L M

Find LM if L is between N and M, NL = 6x – 5, LM = 2x + 3 and NM = 30.

a2 + b2 = c2

Example

Pythagorean Triplets

3 4 5

5 12 13

7 24 25

9 40 41

11 60 61

13 84 85

15 112 113

17 144 145

19 180 181

21 220 221

BC Times

Distance Formula

Used to measure the distance between two points on a coordinate plane.

Example

Recap

H G I

Recap

Recap

L M N

Recap

Caution – Answers Ahead

Study Guide 1-4

Study Guide 1-4

Homework

SG & P Section 1-4 Enrichment 1-1