Warm Up 08.26.11Week 2

•R•Q •S•T

P

1) Name an Obtuse angle?

2) Acute angle?

3) Straight angle?

Geometry1.6 Day 1

I will identify Vertical Angles and Linear Pairs

Vertical Angles

Their sides form two pairs of opposite rays. Vertical angles are congruent.

Ex 11 234

∠4 and ∠2 are vertical angles

∠3 and ∠1 are vertical angles

∠4 ≅ ∠2 ∠3 ≅ ∠1

m∠4 = m∠2

m∠3 = m∠1

Ex 2

∠1 and ∠2 are vertical angles

1

if the m∠1 = 150º, then the m∠2 = _____

2

150º

m∠1 = m∠2

150º = ∠2

∠1 ≅ ∠2

Ex 3

∠QPR and ∠TPS are vertical angles

( 7x – 10 )⁰

( 2x + 55 )⁰

•R•Q •S•T

P

m∠QPR = m∠TPS 7x – 10 = 2x + 55 7x - 2x – 10 = 55

5x – 10 = 55

5x = 55 + 10 5x = 65 x = 13

Find the Variabl

e

∠QPR ≅ ∠TPS

Ex 4

Linear Pairs

Linear Pair angles are adjacent angles that add up to 180º and their noncommon sides

are opposite rays.

1 2

∠1 and ∠2 are linear

pairs

m∠1 + m∠2 = 180º

Ex 5

∠1 and ∠2 are linear pairs

m∠1 + m∠2 = 180º

1 25º

m∠1 + 25º = 180º

m∠1 = 180º - 25º

m∠1 = 155º

2

Ex 6( 2x – 13 )º

( 3x + 33 )º

linear pairs 2x – 13 + 3x + 33 =

180 5x + 20 = 180

5x = 180 - 20 5x = 160

x = 32

x = 32

2x – 13

2( 32 ) – 13

64 – 13

51º

3x + 33

3( 32 ) + 33

96 + 33

129º

51º + 129º = 180º

Ex 7

∠6 and ∠7 are linear Pairs

6

if the m∠6 = 145º, then the m∠7 = _____

7

35º

m∠6 + m∠7 = 180º 145º + m∠7 = 180º

m∠7 = 180º - 145ºm∠7 = 35º

Quiz : Textbook page 48, 23 – 30 all

Review

Quiz : Textbook page 48, 24 – 33 all

Linear pairs add up to ______º.

Do 1:( 9x – 6 )

( 7x + 6 )

•R•Q •S•T

P