1TH/Vwo §4.5 Drawing angles

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

§ 4.5 Drawing angles

+  Before doing § 4.5,

     you will PRACTICE § 4.4 Measuring angles once more!

+ Note for next lessons: always your 

    GEO TRIANGLE + COMPASSES!

Practising measuring angles, in pairs (1). 

Step by step:

1. Open your Notebook

2. Take your GEO TRIANGLE and a PENCIL from your pencil case

3. Draw an ACUTE ANGLE and an OBTUSE ANGLE in your Notebook

Practising measuring angles (2)

4. Measure both angles with your geo triangle

5. Write your two results at the BACK of the page 

(so: seperate from your angles!)

 (3):

6. Exchange your Notebook with your neighbour

7.  Measure your neighbour's two angles

8. Write both results next to the angles

                        (4)

9. Now COMPARE your own results to your neighbour's!

10. Exchange back your Notebooks

11. Discuss shortly: are your measurements equal or not?

       If the difference is more than 2 degrees, measure again to see who's right!

12. However, if the difference is enormous, what will be the reason then?!

Sometimes a huge difference in degrees comes when measuring.
The reason for this is probably ...

Drawing angles

When drawing angles don't forget to include an ARC (boogje) to indicate which angle you drew and to LABEL the angle with a CAPITAL LETTER.

Next come up a dutch Movie. 

It's the only movie I found in which a geo triangle was used.

Other films used a compass rose.

Now it's your turn to try it out!

Do § 4.5 Drawing angles, p.144-147

Start with exercise 34, skipping 33.

In short time we will look at:

 DRAWING a TRIANGLE. 

For doing exercises 36. t/m. 39.

Drawing triangles - a MOVIE.

How to draw a triangle?

This movie demonstrates it in a clear way.

The teacher first makes a rough sketch.

Only then he makes the precise triangle!

Explanation number 2:

If the Movie wasn't clear to you, then the book might be better for  you:

on p.145 the DRAWING of a TRIANGLE  is also explained!

STUDY this carefully, before doing exercise 36 and further!

Next slides show it to you.

Homework Time:

+  Make, correct, take pics and hand in, in GC: 

     §4.5 Drawing angles.

+ Note for next lesson: bring your COMPASSES!