Welcome to class

The warm up is Lesson 1.2 on theback table

5 6

8

Does not make sense. A segment + a number does not equal a number

Does not make sense. No such notation.

22

28

4

Let’s grade your homework

Measuring Angles

Please get:♥One piece of patty paper

♥Protractor♥Your notes

With the straight edge, draw these angles on your patty paper (DO NOT FREE HAND):

S R P Q

CONGRATULATIONS!!You have just created your first set of ADJACENT ANGLES.

ADJACENT ANGLES share a vertex and a ray but they can’t overlap.

Measure each angle.Do you notice anything?

m>PQS = m>SQR =m>PQR =

Angle Addition Postulatem PQS + m SQR = m PQR

P

Q

S

R

Which one makes sense?

A + B = 85°

Or

m A + m B = 85°AB

Angle Congruence Postulate

♥ If two angles have the same measure, then they are congruent.

♥ the converse is also true:If two angles are congruent, then they have the same measure.

Can you write a biconditional?

• COMPLEMENTARY Angles – Exactly two angles whose sum is 90°. Each angle is a COMPLEMENT of the other.

• SUPPLEMENTARY Angles = Exactly two angles whose measure is 180°. Each angle is a SUPPLEMENT of the other.

A 60° 120°

C

30°

B

Complementary angles are A and B

A and B are complements of each other

A and C are supplementary angles

A and C are supplements of each other

Are you

doing

ok?

Linear Pair Property

If two angles form a line, they are a linear pair AND are supplementary.

125° 55°

AnglesRIGHT ANGLE = 90°

INDICATED BY THE BOX IN THE CORNER

ACUTE ANGLE = angle less than 90°OBTUSE ANGLE = angle more than 90° but less

than 180°STRAIGHT ANGLE = angle that equals 180°REFLEX ANGLE = angle greater than 180° and

less than 360°.

Whiteboards

Please get a whiteboard, marker,

and eraser.

Doodle time starts in one minute.

Your assignment

3.1Packet