2TH/vwo §3-5 Calculations using similarity (p. 86)

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 3

Calculations using 

similarity (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 unknown angles using similarity
  
• Calculate unknown sides using similarity
  

How do you calculate the unknown length in similar triangles?

1. Make a sketch of the triangles next to each other in the same position and include the known measurements. 
2. Check that the triangles are similar.
3. Calculate the scale factor.
4. Calculate the unknown length.

Voorbeeld van docent (p. 86)

IA

32 A, respectively

1. C and D
2. D and C
3. C and B
4. D and B

32b

1. 3,5
2. 4,5
3. 5,5
4. 5,7

32c

1. 18,48 cm
2. 16,43cm
3. 16,25 cm
4. 15,87 cm

3a

1. All angles are equal (F-angles)
2. All angles are equal (Z-angles)
3. All angles are equal (angles of triangle 180)
4. Same scale factor

33b

1. 1
2. 2
3. 3
4. 4

33c

1. 14
2. 5
3. 4,5
4. 3,5

33d

1. 1
2. 2
3. 3
4. 4

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: M6 and M7 (p. 97)

Challenge: C3 (p. 98)

 37, 38, 39

(p. 88)