# 3Tvwo §8.2 (A) and §10.2 (B)

Welcome ...
+ to this first Long distance Lesson
+ Thanks to the technical developements you can work on ...
+ by yourself, but also a bit together,
+ starting right now with this LessonUp!

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Slide 1: Slide
WiskundeMiddelbare schoolvwoLeerjaar 3

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

Lesson duration is: 50 min

## Items in this lesson

Welcome ...
+ to this first Long distance Lesson
+ Thanks to the technical developements you can work on ...
+ by yourself, but also a bit together,
+ starting right now with this LessonUp!

#### Slide 1 -Slide

A: §8.2 Grouping data
B: §10.2 Altitude
An introduction for B follows now!
It only takes a few slides and then I've got an introduction to your paragraph!)

#### Slide 2 -Slide

So the subject for today is: the ALTITUDE (=hoogtelijn).
Of course the Challenge path is your learning path!

#### Slide 4 -Slide

Comment:
As you can see in the previous picture:
+ an altitude (=hoogtelijn) is used to measure the distance from a vertex to the opposite side
+ an altitude can be outside the triangle!

#### Slide 5 -Slide

As you see in the Solution of 12a, you need:
+ a pencil
+ a geo triangle (straight lines, angle of 40 degrees)
+ a pair of compasses
+ forgetting these things is impossible now, because you are at home!!

#### Slide 6 -Slide

Here you see the Solution of 14c.
Question: What Rules for Angles of Triangles are used here?
Answer this in the next slide!

#### Slide 7 -Slide

These rules for triangles are:
A
opposite angles are equal
B
the angles of a triangle are 180 degrees together
C
a straight angle is 180 degrees
D
a triangles always has an obtuse angle

#### Slide 8 -Quiz

1st:  the 3 angles together are 180 degrees
2nd: a straight angle is 180 degrees
3rd: opposite angles are equal

#### Slide 10 -Slide

Homework time.
Good luck, doing §8.2!
(In Classroom or Study square.)

#### Slide 11 -Slide

Math A, §8.2 Grouping data
A few fine points!
+ first a bit of Theory, then
+ 2 questions

#### Slide 12 -Slide

Study this closely; you can also use book 3B, p.15.

#### Slide 13 -Slide

There is something tricky about 'intervals'!
That's why we go on a bit on it.

Question:
What are the midpoints of these classes?
Fill in in next slide!

#### Slide 14 -Slide

The midpoints of the classes are:
A
3 8 13 mm
B
2 8 12 mm
C
2 7 12 mm
D
2.5 7.5 12.5 mm

#### Slide 15 -Quiz

Why?
The first class goes from 0 to 5 (5 not included),
so in fact from 0 to 4.999999......
Now it is clear that 2.5 is in the middle.

#### Slide 16 -Slide

Answer this question on the next slide!
(You might be surprised.)

#### Slide 17 -Slide

Number of tickets is ...
A
42
B
42.5
C
43
D
43.5

#### Slide 19 -Slide

Homework time
+  Good luck doing §8.2!
+  When you are stuck and the Solutionsbook is not clear enough for you,
+  you may mail me and I will provide you with an explanation.
ncf.hauwert@tabor.nl