# Angles

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Slide 1: Slide
Middelbare schoolvwoLeerjaar 1

This lesson contains 13 slides, with interactive quizzes and text slides. Lesson duration is: 15 min

## Items in this lesson

#### Slide 1 -Slide

Angles
An angle is the space between two line segments
Just like we measure the length of a line segment
or we calculate the area of a 2D-shape
or the volume of a 3D-shape

#### Slide 2 -Slide

Angles
First of all we need to give angles a unit, degrees
A full angle (a circle) is always 360 degrees

#### Slide 3 -Slide

Angles
If we draw a straight line, and we measure the top half of the line we get a straight angle which is 180 degrees
We write:

A=180°

#### Slide 4 -Slide

Angles
Now if we cut the straight angle in half we get a right angle
Since angle B is between points A and C
We can write

Or we write
This has exactly the same meaning

ABC=90°
B=90°

#### Slide 5 -Slide

Angles
Now there are also angles that are smaller than right angles and that are larger than right angles.
Acute angles are always between 0 and 90 degrees
Obtuse angles are always between 90 and 180 degrees

#### Slide 6 -Slide

Angles
In the next few slides you will be tested on your knowledge about angles.

#### Slide 7 -Slide

How many degrees is a right angle?
A
0
B
360
C
90
D
180

#### Slide 8 -Quiz

How many degrees is a straight angle?
A
0
B
360
C
90
D
180

#### Slide 9 -Quiz

How many degrees is a full angle?
A
0
B
360
C
90
D
180

#### Slide 10 -Quiz

What kind of angle do you see on the right?
A
Straight angle
B
Obtuse angle
C
Acute angle
D
Right angle

#### Slide 11 -Quiz

What kind of angle do you see on the right?
A
Straight angle
B
Obtuse angle
C
Acute angle
D
Right angle

#### Slide 12 -Quiz

What kind of angle do you see on the right?
A
Straight angle
B
Obtuse angle
C
Acute angle
D
Right angle