# 1819 C2X §8.Refresh & §8.1

What number should be written on the dots?
1.25 km = .... m
1 / 18
Slide 1: Open question
WiskundeMiddelbare schoolhavo, vwoLeerjaar 2

This lesson contains 18 slides, with interactive quizzes and text slides.

Lesson duration is: 50 min

## Items in this lesson

What number should be written on the dots?
1.25 km = .... m

#### Slide 1 -Open question

What number should be written on the dots?

50cm2=...mm2

#### Slide 2 -Open question

Converting units of length and area
Units of length are multiplied/divided with steps of 10
Units of area are multiplied/divided with steps of 100

#### Slide 3 -Slide

Enclosing figures (R3g)
Calculate the area of figures ABCD, KLM and PQR by enclosing.

When enclosing a figure, you use the fact that the area of a right-angled triangle is half a rectangle.

#### Slide 4 -Slide

Enclosing figures (R3g)
Calculate the area of figures ABCD, KLM and PQR by enclosing
Area ABCD:
Area red square =
Area triangles on outside =

Area ABCD =
44=16
231=1.5
1641.5=10

#### Slide 5 -Slide

Pythagoras' theorem
If you know two sides of a right angled triangle, you can calculate the third side using Pythagoras' Theorem:

#### Slide 6 -Slide

Pythagoras' theorem
Calculate the lenght of side AC in triangle ABC, where BC = 13, AB = 5 and angle A is 90°

#### Slide 7 -Slide

Pythagoras' theorem
Calculate the lenght of side AC in triangle ABC, where BC = 13, AB = 5 and angle A is 90°

#### Slide 8 -Slide

Pythagoras' theorem
Calculate the lenght of side AC in triangle ABC, where BC = 13, AB = 5 and angle A is 90°

#### Slide 9 -Slide

Pythagoras' theorem
Calculate the lenght of side AC in triangle ABC, where BC = 13, AB = 5 and angle A is 90°

#### Slide 10 -Slide

Area of triangles
Make exercise 1  from §8.1

timer
4:00

#### Slide 11 -Slide

Area of triangles
timer
4:00

#### Slide 12 -Slide

Area of triangles

#### Slide 13 -Slide

Base and height of a triangle
The base is one side of a triangle.
The height  is the distance from the base to the opposite vertex.
The height is perpendicular to the base.
In a triangle there are 3 base/height combinations.

#### Slide 14 -Slide

Base and height of a triangle
The height of a triangle can also be outside the triangle, perpendicular to the line through the base.

#### Slide 15 -Slide

Area of a triangle
The area of a triangle can be calculated with the formula:

This can be shortened to:
or

#### Slide 16 -Slide

Area of a triangle

#### Slide 17 -Slide

HW Tuesday 11-6
Make and correct §8.Refresh and §8.1