April 21st - Your next hand-in day will be Wednesday, April 30th -

Draw 5 2D Shapes.Using a dotted line, draw a line of symmetry through each shape.

Do any of your shapes have more than one line of symmetry?

- Similarity, Transformations, & Symmetry -

Approximately April 21st to May 14th

This unit will help you develop an understanding of the Geometry of 2D

Shapes. Geometric understanding is formally

used in careers like architecture, engineering, design, & surveying.

We will learn how to work with:- Scale Diagrams- Similar Shapes- Line Symmetry & Rotational Symmetry

As a group, review the flags of the provinces/territories in Canada.

Which one(s) have lines of symmetry?

What Is Line Symmetry?

- There is/are a line(s) that divide the shape into two congruent parts- Called the line of

symmetry or line of reflection

- They can have more than one line of symmetry!

What Is Line Symmetry?

- It DOES NOT mean that the line simply cuts a shape in half

- Each side has to be exactly the same- If they folded on top of

another, it would be a perfect match

On the worksheet, Master 7.19:- Identify how many lines of

symmetry each shape has

One the back of the worksheet:- Sort the shapes according to the

number of lines of symmetry that they have

- Which shapes do not have any lines of symmetry?

Which shapes have 1 line of symmetry?A, D, G, I

Which shapes have 2 lines of symmetry?B

Which shapes have 3 lines of symmetry?None

Which shapes have 4 lines of symmetry?F, H

Which shapes have no lines of symmetry?C, J, K

Symmetrical Logos!

You and a partner are designing a logo for (insert interesting idea here).

Your logo must include:- 5 shapes that have their own

unique lines of symmetry- Overall symmetrical design- At least 3 different colours

April 22nd - Your next hand-in day will be Wednesday, April 30th -

How many lines of symmetry do each of these hazard symbols have?

Example ONE

What lines of symmetry exist in each tessellation below?

Example ONE

What lines of symmetry exist in each tessellation below?

Example TWO

Which triangles are related to the red triangle by a line of reflection?

Example TWO

Which triangles are related to the red triangle by a line of reflection?

Example THREE

Shape ABCD is partof a larger shape.If line AD serves asa line of symmetry,draw the remainingportion of theshape.

Example THREE

Shape ABCD is partof a larger shape.If line AD serves asa line of symmetry,draw the remainingportion of theshape.

Line Symmetry Questions

Page 358, Questions 4-6

Page 359, Questions 9-10

April 23rd - Your next hand-in day will be Wednesday, April

30th -

How many lines of symmetry does each logo have?

April 28th - Your next hand-in day will be Wednesday, April

30th -

How many lines of symmetry does each logo have?

April 29th - Your next hand-in day will be Wednesday, April

30th -

How many lines of symmetry does each logo have?

April 30th - Hand-In Day-

How many lines of

symmetry does each logo have?

May 5th - Your next hand-in day is Tuesday, May 13th -

Maps usually feature a Scale Factor like the one displayed below.

Use the image to describe what the Scale Factor is telling us.

- A Scale Diagram is an image that is an enlargement or reduction of another image- Enlargement =

bigger- Reduction = smaller

You have been handed a picture of a 2D or 3D shape, with measurements.

Find a person in the classroom who has the same shape as you, but the image

has been enlarged or reduced. 6cm 3cm

2cm 4cm

Scale Factors

- To determine how much an image is enlarged or reduced by, use the following formula:

- Scale > 1 Enlargement

- Scale < 1 Reduction

Length of vertical segment on the scale diagram=

Length of vertical segment on the original diagram=

Length of horizontal segment on the scale diagram=

Length of horizontal segment on the original diagram=

Scale Factors

- The scale factor of the image is or 2.5

Scale Factors- A mosquito

measures 12mm in length

- A newspaper picture of a mosquito measures 4.5cm in length

Scale Factors- A mosquito

measures 12mm in length

- A newspaper picture of a mosquito measures 4.5cm in length

Scale Factors- An image measured

9cm by 6cm - It needs to be

enlarged by a scale factor of:

- What dimensions will the enlargement have?

Scale Factors- An image has the

measurements seen here

- It needs to be enlarged by a scale factor of:

1.5

- What dimensions will the enlargement have?

Scale Factors- An image has the

measurements seen here

- It needs to be reduced by a scale factor of:

0.25

- What dimensions will the reduction have?

Scale Factor Questions

Pg 323 Qs 4, 5, 11Pg 329 Qs 5, 7, 12

May 6th - Your next hand-in day is Tuesday, May 13th -

Draw a 2D shape that has a rotational symmetry with an order of 6.

Label the measurements of your shape.

Enlarge your shape by a scale factor of 4.5.

Scale Factor Word Problems

Complete the questions provided on the worksheet.

Place all answers on a piece of loose leaf & remember to include diagrams!

May 7th - Your next hand-in day is

Tuesday, May 13th -

You are provided with the following shape:If it is to be reduced by a scale factor of 3/4, what will its new measurements be?Draw & label a diagram of the

reduction.

Similarity

- Two triangles are similar if the only difference is:- Size- Rotation

- All of the triangles in the image to the right are considered similar

Similar Triangles. (Accessed 2014). Uploaded by Math is Fun. Available online at: http://www.mathsisfun.com/geometry/triangles-similar.html

Similarity

- Similar triangles have to have:- All of their angles

equal OR- Corresponding

sides have the same ratio (they are scale diagrams of one another)

Similar Triangles. (Accessed 2014). Uploaded by Math is Fun. Available online at: http://www.mathsisfun.com/geometry/triangles-similar.html

Representing Similar Triangles

- The symbol ∠ is used to represent angle

- These 2 triangles are similar because:

∠ A = ∠ Q = 75o

∠ B = ∠ R = 62o

∠ C = ∠ P = 43o

Representing Similar Triangles

- When comparing 2 triangles, order the letters to match the angles:

(ex) ∆ABC ~ ∆QRP- AB matches QR- BC matches RP- AC matches QP

Similar Triangles

Identify how the 2 triangles are similar

Similar Triangles

How tall is the totem pole to the nearest tenth of a

meter?

Similar Triangles

Page 349-351

Qs 4-7, 9-12

May 12th - Your next hand-in day is

Tuesday, May 13th -

You are provided with the following shape:If it is to be reduced by a scale factor of 3/4, what will its new measurements be?Draw & label a diagram of the

reduction.

May 13th - Hand-In Day!! April 30th - Today -

Use similar triangles to find the value of x.