2TH §3.4 Calculating using similarity

§ 3.4 Calculating using similarity
That's the content for today!

1 / 11
suivant
Slide 1: Diapositive
WiskundeMiddelbare schoolhavo, vwoLeerjaar 2

Cette leçon contient 11 diapositives, avec quiz interactif et diapositives de texte.

time-iconLa durée de la leçon est: 50 min

Éléments de cette leçon

§ 3.4 Calculating using similarity
That's the content for today!

Slide 1 - Diapositive

Questions about the homework?
§3.4: S25, 27, S28

Slide 2 - Diapositive

Slide 3 - Diapositive

Slide 4 - Diapositive

Scale factor and perimeter
Perimeter rectangle A = 2 + 1 + 2 + 1 = 6 cm

Perimeter rectangle B = 4 + 2 + 4 + 2 = 12 cm
Perimeter rectangle C = 6 + 3 + 6 + 3 = 18 cm
Perimeter rectangle D = 8 + 4 + 8 + 4 = 24 cm

12 = 6 x 2; 18 = 6 x 3; 24 = 6 x 4.
The perimeter is multiplied by the scale factor.



Slide 5 - Diapositive

Scale factor and area (1)
Rectangles B, C and D are
enlargements of rectangle A.

The scale factors are:
B: 2 (meaning: when you 
multiply length and width of picture
A by 2, you get picture B)
C: 3
D: 4

Slide 6 - Diapositive

Scale factor and area (2)







The area is multiplied by the scale factor squared!

Slide 7 - Diapositive

Scale factor and area
When the dimensions (length/width/height) of a figure are multiplied by a factor s, the perimeter is also multiplied by s, but the area is multiplied by      .

(When you learn about volume you will find that the volume is multiplied by      )
s2
s3

Slide 8 - Diapositive

Homework
  • Do §3.4: Exercise 28, 29, 30
  • Do §3.5: Exercise 31

  • Correct your answers with the Solutionsbook and a red pen

Slide 9 - Diapositive

Slide 10 - Diapositive

What did you learn today?

Slide 11 - Carte mentale