2TH/vwo Ch4 REFRESH

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Ch 4 SIMILARITY

What is this?

Write your first idea that comes up when you see the word

'similarity' in the next slide!

'similarity' makes me think of ....

The triangles 

on the right 

are SIMILAR

This gives you an

idea of similarity.

A recap from 1st form(1):

- open your Notebook on a new page

- write down 'Ch 4 Similarity' on top

- write down what you still know about ANGLES

- think of types of angles, sizes of angles,

   angles in triangles and quadrilaterals, calculations, etcetera! 

- KEEP YOUR TEXTBOOK CLOSED NOW !

A recap from 1st form(2):

Compare with your neighbour what you remember about angles.

Add what your neighbour wrote down and you didn't.

In a few minutes we will share this with the class. 

Let's share some results with all of us.

After you worked on this, let me show you what the book has to offer us on ANGLES!

The following THEORY is taken from the Refresh from Ch4.

Pay attention carefully, because you need this information for doing the Homework!

Let's CORRECT a MISTAKE :

In p.124, R1a there is something 

terribly wrong...

See next slide.

CORRECT this in your PAPER BOOK, please:

R1a.   ............ one of the angles ...........

has to be:

             ............ angle A ...........

Let's do R2 together!

Open your Textbook on p.124/125

Get your:

- geo

- pencil

from your pencilcase.

Attention:

A   SKETCH  doesn't have to be precise! 

Use your PENCIL for DRAWING, as always.

An important check is this:

are the angles D and E acute (o to 90 degrees) or obtuse (90 to 180 degrees)?!

Go ahead and make  your sketch!

My SOLUTION comes in  next slide.

Do the tasks below PRECISELY ! It's NOT a SKETCH.

Using: pencil and geo triangle.

Fill in your answers in your Notebook but also in the next slide!

Angle F = ....
The sum of the 3 angles is ....

Compare your answers to the ones below!

Your angles may differ 1 or 2 degrees from those, below.

Homework time

Do: p.124/125:    REFRESH Ch4 Similarity

+ Check your answers with the Solutionsbook,

    using another colour pen.

+  Take a few pics and

+  send'm in in GC.

+ Finished? Finish 'unfinished business' from Ch 2 Roots !