Warm Up 08.22.11Week 2

1) 3x + 11 = 38

2) 3( 5x – 8 ) = 21

Geometry1.4 Day 2

I will use angle postulates

A

C•

•

B

Ex 1

P 3 Protractor Postulate

The measure of ∠ABC is the absolute value of the difference between the numbers of BA and BC.

Acute Angle

measuring less than 90º but more than 0º

Ex 2

Right Angle

angle measuring 90º

Ex 3

Obtuse Angle

angle measuring more than 90º but less than 180º

Ex 4

Straight Angle

angle measuring 180º

Ex 5

•P

•S•RQ

Named for their angle or sides

PQS or SQP

SQR

RQS

PQR RQPor

or

Q

Ex 6

Angle Names

Name the Vertex and Sides:

•G

F

H•

Vertex: F

Side: FH

Side: FG

Ex 7

m The measure of angle A : no stated points on the rays

A

A

m ∠ A = 50º

Ex 8

Points on the rays are stated.m ∠ BAC

∠BAC ≅ ∠EDF

Angles are Congruent

Measures are Equal

m∠BAC = m∠EDF

50º 50º

50º = 50º

Ex 9

Do 1:

65º

65º•B A

C•

•

•

D

E

Is ∠ BAC ≅ ∠ EAD?

115º

115º

A

Interior Point

between each side of an angle ( A )

•

Exterior Point

outside or not on the angle ( B )

B•Ex 10

Ex 11

∠QSR adjacent to ∠RSP

•R

•P

•TS•Q

Adjacent Angles

Share a vertex and one side, but no common points

∠QSR is not adjacent to ∠PST

Review

Assignment

Textbook page 29, 1 – 25 all

What is the difference between a straight angle and a supplementary angle?

Do 3:

•G

F

H•

What can be the 3 names of this angle?