Thursday, January 19th • Please complete the warm up and write down

your homework• Please have your own angle matches out

Warm Up1. Simplify

2. Write an expression for 2 times three more than twice a number

250 7 4 6

Corny Joke of the Day

Why did Wesley bring a ladder to

school?

Because he wanted to get to

high school

Angle Match• Using the cards you made last

night…..• Switch your cards with the person

who is sitting to your left • Then, try to categorize their cards

into the four main angle types!

Symmetry

OUR MISSION

Learn to identify line symmetry.

Making Unusual ShapesFold your piece of paper in half Cut an unusual shape from it Unfold it What do you notice?The parts of the shape What does the folded line

represent?

A figure has line symmetry if it can be folded or reflected so that the two parts of the figure match, or are congruent. The line of reflection is called the line of symmetry.

Part 1 Lines of symmetry in regular polygons

Regular polygons: All side lengths and angles are

congruent

Can you find the rule?Find the number of lines of

symmetry in each shape and fill out the chart.Shape Number of Sides Lines of

symmetryTriangle

Square

Pentagon

Hexagon

Octagon

4 lines of symmetry

DiscoveryFor a regular

polygon the lines of symmetry is the same as

the number of sides!

Fun FactA dodecagon is a 12-

sided regular polygon. This means that it has

___________lines of symmetry!

Part 2 Determining if the lines given are the lines

of symmetry

Determine whether each dashed line appears to be a line of symmetry.

The two parts of the figure appear to match exactly when folded or reflected across the line.

The line appears to be a line of symmetry.

#1

Determine whether each dashed line appears to be a line of symmetry.

The two parts of the figure do not appear congruent.

The line does not appear to be a line of symmetry.

#2

Determine whether each dashed line appears to be a line of symmetry.

The two parts of the figure do not appear congruent.

The line does not appear to be a line of symmetry.

#3

Determine whether each dashed line appears to be a line of symmetry.

The two parts of the figure appear to match exactly when folded or reflected across the line.

The line appears to be a line of symmetry.

#4

Group DiscussionHow many lines of symmetry does the following shape have?

NOT EVERY SHAPE HAS A

LINE OF SYMMETRY

1 line of symmetry

Is there a line of symmetry. If so, how many?

Smile Symmetry

LOGO SYMMETRY