Notetaking with Vocabulary

Name _________________________________________________________ Date _________

1.5

Notetaking with Vocabulary For use after Lesson 1.5

In your own words, write the meaning of each vocabulary term.

angle

vertex

sides of an angle

interior of an angle

exterior of an angle

measure of an angle

acute angle

right angle

obtuse angle

straight angle

congruent angles

angle bisector

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Name_________________________________________________________

1.5

Date __________

Notetaking with Vocabulary (continued)

Postulate 1.3 Protractor Postulate   Consider OB and a point A on one side of OB. The rays of the  form OA can be matched one to one with the real numbers from 0 to 180.

3 15 0 4 01 0 40 0 10 180 170 1 20 60

A

O

B

170 180 60 0 1 20 10 0 15 0 30 14 0 4

The measure of ∠ AOB , which can be written as m∠ AOB , is equal to the absolute value of the difference between the   real numbers matched with OA and OB on a protractor.

80 90 10 0 70 10 0 90 80 110 1 70 2 60 0 110 60 0 1 2 3 50 0 1 50 0 3 1

Notes:

Core Concepts Types of Angles

A

A

A

acute angle Measures greater than 0° and less than 90°

A

right angle

obtuse angle

straight angle

Measures 90°

Measures greater than 90° and less than 180°

Measures 180°

Notes:

Postulate 1.4 Angle Addition Postulate Words If P is the interior of ∠ RST , then the measure of

∠ RST is equal to the sum of the measures of ∠ RSP and ∠ PST . Symbols If P is in the interior of ∠ RST , then

R m∠RST S

m∠RSP m∠PST

P

m∠ RST = m∠ RSP + m∠ PST .

Notes:

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Name _________________________________________________________ Date _________

Notetaking with Vocabulary (continued)

1.5

Extra Practice In Exercises 1– 3, name three different angles in the diagram. 1.

2.

E F

G

3.

T

K

Q

H

N

S

L

M

R

In Exercises 4– 9, find the indicated angle measure(s). 4. Find m∠JKL.

5. m∠RSU = 91°. L

Find m∠RST .

6. ∠UWX is a straight angle.

Find m∠UWV and m∠XWV .

U

M

U

X

W

(x + 20)° x° 85°

31°

S

K

J

69°

V

T R





7. Find m∠CAD

8. EG bisects ∠ DEF .

9. QR bisects ∠ PQS .

and m∠BAD.

Find m∠DEG and m∠GEF .

Find m∠PQR and m∠PQS .

D

Q

C

A

(x + 15)° (5x + 57)°

S (−3x + 130)°

D

P

92° E

G

B

(4x − 10)°

R

F

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Geometry Student Journal

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