1TH/Vwo §4.4 Measuring angles

§4.4 Measuring angles ...
is on the menu today!

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WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

This lesson contains 26 slides, with interactive quizzes, text slides and 1 video.

time-iconLesson duration is: 50 min

Items in this lesson

§4.4 Measuring angles ...
is on the menu today!

Slide 1 - Slide

At the very first ...
Your teacher will demonstrate how to MEASURE angles
with a GEO triangle.

Slide 2 - Slide

1TH/Vwo §4.4 Measuring angles

First a quick check on your knowledge of §5.3 !
Try to give the good answers, gaining points.

Slide 3 - Slide

an angle of 90 degrees is a(n) ...
A
straight angle
B
obtuse angle
C
right angle
D
acute angle

Slide 4 - Quiz

An angle of 47 degrees is a(n)
...... angle.
A
obtuse
B
right
C
acute
D
straight

Slide 5 - Quiz

An obtuse angle could be ...
A
99 degrees
B
36 degrees
C
90 degrees
D
180 degrees

Slide 6 - Quiz

I wonder if    .....
+ you had all questions right, knowing all about it, or
+ you had both wrong, having no clue
However, let's look back at the Theory from §4.3 !

Slide 7 - Slide

Slide 8 - Slide

Slide 9 - Slide

Slide 10 - Slide

Attention (1):
+ a right angle has :
+ an acute angle has a number of degrees between  0  and  90.
90°

Slide 11 - Slide

Slide 12 - Slide

Slide 13 - Slide

Attenzione (2):
+ an obtuse angles has a number of degrees between 90 and 180
+ a straight angle has 180 degrees

Slide 14 - Slide

Ready for §4.4 Measuring angles?
Soon comes a Movie.

Slide 15 - Slide

Measuring angles ...
+ you can do with the GEO TRIANGLE:
  using the PROTRACTOR ( =gradenboog) on it
+ that's the semi-circle (=half a circle) with the degrees from 0 - 180 degrees
    written on it
+ just watch the following Movie and be amazed!

Slide 16 - Slide

Ruben ...
surely knows how to explain things in a simple way!
By the way, I offer you this Dutch movie, because it was the only one I found that used a Geo triangle and not a compass rose!

Slide 17 - Slide

Slide 18 - Video

Slide 19 - Slide

Slide 20 - Slide

Slide 21 - Slide

First 2 special things:

+  Which angle is meant?
+ How to measure an angle if the arms are too short?
  Just watch the next slides!

Slide 22 - Slide

If the arms of an angle are too short, just ....
extend them!
So in this case
you take your pencil and 
make both arms longer,
so that the geo can be used well! 
(You may even do this in your Textbook, 
but with a PENCIL, of course!)

Slide 23 - Slide

Slide 24 - Slide

In the picture you see many different angles:
+ angles A, C and E , but also
+ angles B1, B2, D1 and D2 !
+ so by the added number you
   know which part of the angle 
   is meant. Great!


Slide 25 - Slide

Time for Homework
+ Do:    § 4.4 Measuring angles
+ Check your work with the Solutionsbook
+ take pics and
+ send in all the stuff on Google Classroom

Slide 26 - Slide