3-6 Area increase with similar triangles (p 87)

• Wiskunde
• Middelbare school
• havo
• Leerjaar 3

Surface area with

similar triangles (p. 86)

What you need:

- Textbook, writingbook, iPad

- Pen, pencil, geotriangle

- Calculator

Schoolbags in the cuboard

Phones in the phonebag

Bluetooth 

- ON

- VPN off

Lesson goal

• Calculate the unknown surface area with similar triangles

The surface area is 1 cm²

scale factor

= 4:2

= 2

Therefore this surface area is 

       2² x 1 cm² = 4 cm²

IA

34a) PQ =

1. 22.5 cm
2. 27 cm
3. 9 cm
4. 7,5 cm

34a) PR =

1. 22.5 cm
2. 27 cm
3. 9 cm
4. 7,5 cm

34a) PQ =

1. 4.15 cm en 3,45 cm
2. 4.24 cm en 3,54 cm
3. 4.5 cm en 3,5 cm
4. 4.0 cm en 3,5 cm

Dont make the drawings in A and B

35d

1. 0,75
2. 1,1
3. 2,6
4. 0,5

32 A, respectively

1. 7,67
2. 8,05
3. 8,55
4. 8,63

Try on your own

1, 2, 5 and 7

TRY ON YOUR OWN...

RULES:

• In your writingbook
• Use: Textbook
• Discussion when you are stuck is allowed

Extra excercise: B8 (p. 95)

 40, 41, 42

(p. 89)