13.3 Calculating angles_1allr

Which exercises/theory should I discuss on the board?
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Slide 1: Mind map
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This lesson contains 21 slides, with interactive quizzes, text slides and 1 video.

Lesson duration is: 50 min

Items in this lesson

Which exercises/theory should I discuss on the board?

Slide 1 -Mind map

More types of angles
You already know acute, right and obtuse angles, but there are more types of angles!

Slide 2 -Slide

Which angle's size is
between 90° and 180°?

Slide 4 -Video

Did you notice...

Slide 5 -Slide

Types of angles
Acute angle: between 0° and 90°
Right angle: 90°
Obtuse angle: between 90° and 180°
Straight angle: 180°
Reflex angle: between 180° and 360°
Full angle: 360°
(A full angle is also called a full turn)

Slide 6 -Slide

Both a straight angle and a full turn look like a straight line. The arc is used to show it is an angle.

Slide 7 -Slide

Calculating angles
You can use full turns, straight angles and right angles to calculate angles. When calculating an angle you do NOT use your geotriangle to measure the size of an angle.

When more than one angle can be found at the same vertex, numbers are used to indicate the different angles.

Slide 8 -Slide

Calculating angles

Slide 9 -Slide

Opposite angles
Opposite angles are the angles on opposite sides of the point of intersection of two lines. Opposite angles are always equal.

Slide 10 -Slide

Calculating angles
What type of angle is            ?

A4

Slide 11 -Slide

What type of angle is angle A4?
A
Acute angle
B
Right angle
C
Obtuse angle
D
Straight angle

Slide 12 -Quiz

Calculating angles
Which angle is the opposite
angle of             ?

A1

Slide 13 -Slide

Which angle is the opposite of angle A1?
A
A2
B
A3
C
A4
D
A5

Slide 14 -Quiz

Calculating angles
What size is             ?

A2

How many degrees
is angle A2?

Slide 16 -Open question

Calculating angles

(because they are opposite angles)

(because it is a right angle)

A3=A1=57°
A4=90°

Slide 17 -Slide

Calculating angles
and            are together
a ......
A1,A5
A4

Slide 18 -Slide

Angle A1, angle A5 and
Angle A4 are together a ....
A
full turn
B
reflex angle
C
straight angle
D
right angle

Slide 19 -Quiz

Calculating angles
A5=1809057=33°