# 2TH/vwo Ch4 REFRESH

Ch 4 SIMILARITY
What is this?
Write your first idea that comes up when you see the word
'similarity' in the next slide!
1 / 20
Slide 1: Slide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 2

This lesson contains 20 slides, with interactive quizzes and text slides.

Lesson duration is: 45 min

## Items in this lesson

Ch 4 SIMILARITY
What is this?
Write your first idea that comes up when you see the word
'similarity' in the next slide!

#### Slide 1 -Slide

'similarity' makes me think of ....

#### Slide 2 -Mind map

The triangles
on the right
are SIMILAR

This gives you an
idea of similarity.

#### Slide 3 -Slide

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 !
timer
1:30

#### Slide 4 -Slide

A recap from 1st form(2):
timer
1:30

#### Slide 5 -Slide

Let's share some results with all of us.

#### Slide 6 -Slide

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!

#### Slide 9 -Slide

Let's CORRECT a MISTAKE :
In p.124, R1a there is something
terribly wrong...
See next slide.

#### Slide 10 -Slide

R1a.   ............ one of the angles ...........
has to be:
............ angle A ...........

#### Slide 11 -Slide

Let's do R2 together!

Get your:
- geo
- pencil

#### Slide 12 -Slide

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)?!
My SOLUTION comes in  next slide.

timer
2:00

#### Slide 14 -Slide

Do the tasks below PRECISELY ! It's NOT a SKETCH.
Using: pencil and geo triangle.
timer
1:30

timer
1:00

#### Slide 17 -Slide

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

#### Slide 18 -Mind map

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

#### Slide 19 -Slide

Homework time
Do: p.124/125:    REFRESH Ch4 Similarity
using another colour pen.
+  Take a few pics and
+  send'm in in GC.
+ Finished? Finish 'unfinished business' from Ch 2 Roots !