Learn how to classify angles into categories

1. Understanding and Classifying Angles
Friday 25 April 2025

2. Whiteboard Practice:
Whiteboard Rules
1) Silent,
individual
activity
2) Everyone
shows their
board
3) “3… 2… 1…
Show me”
On your boards, draw
these points
A
B
C
D
E
x
x
x
x
x

3. Whiteboard Practice:
Draw line segment AD Draw line segment DA
What polygon would I get
if I joined ADB?
Is there another way I can
make this polygon?
What polygon would I get
if I joined ACEB?

4. It doesn’t always have to be a shape
that is labelled, it could be an angle…

5. Whiteboard Practice:
Y
X
Z
Which diagram represents angle XYZ?
X
Y
Z
E
G
F
Which diagram represents angle EFG?
E
G
F

6. Activity:
XYZ PQR TUV
BCD JKL FGH
STU EFG ABC
DEF WXY LMN

7. Answers:

8. Answers:

9. Before you go…

10. On your whiteboards, draw any quadrilateral

11. What is the correct angle notation for this
shape?
ABCD BDAC
ADBC BDCA
B C
D A

12. •Which of the following statements are true?
Geometry Notation
P
Q
R
∠ 𝑃𝑄𝑅=90° ∠ 𝑃𝑅𝑄=90° ∠𝑄𝑃𝑅=90°

13. •Which of the following statements are true?
Geometry Notation
L
N
M
∠𝐿𝑀𝑁=90° ∠𝑀𝐿𝑁=90° ∠𝐿𝑁𝑀=90°

15. •Which of the following statements are
true?
Geometry Notation
S T
U
∠𝑆𝑇𝑈=60° ∠𝑆𝑈𝑇 =30° ∠𝑇𝑆𝑈=60°
60°
30 °

16. Whiteboard Practice:

17. Whiteboard Practice:
A quarter turn anti-
clockwise

18. Whiteboard Practice:
A quarter turn
clockwise

19. Whiteboard Practice:
A full turn

20. Whiteboard Practice:

21. Silent Settler
Use all 3 points and
name the angle
What was the question?
£300 ÷ 10 = £30
£30 x 3 = £90

22. Understanding and Classifying Angles Friday 25 April 2025

23. Example: N
S
E
W
NE
SE
SW
NW
Tommy is facing South West.
Tommy turns ten full turns.
Which direction is Tommy facing
after ten full turns?
How many degrees did Tommy
turn through?
Did it matter whether Tommy
turns clockwise or anticlockwise?
South West
10×360°=3,600°
No. Multiples of one full turn will give the same
result clockwise or anticlockwise.
Copy into your
books please

24. Full turn
How many degrees is equal to of a turn?
of a turn
?
360° ÷8=45° 45°×3=135°
135°

25. Whiteboard Practice:
Complete the sentence
10
100
1
10
360°
3600°
36°
36000°

26. Classifying Angles

27. How many different types of angle
do you know?
Type of angle angle,
Acute angle
Right angle
Obtuse angle
Reflex angle
0 °<𝑥 <90 °
𝑥=90 °
90°<𝑥<180°
180°<𝑥<360°
Copy into your
books please

28. How can we classify an angle without measuring it?
Half turn
Acute angle
Obtuse angle

29. Is the statement below true or false?
Interior angles in regular polygons
are never reflex.
True

30. Whiteboard Practice:
What kind of angle is this?
Obtuse Straight Reflex
Right Acute

31. Whiteboard Practice:
What kind of angle is this?
Obtuse Straight Reflex
Acute
Right

32. Whiteboard Practice:
What kind of angle is this?
Straight Reflex
Acute
Right Obtuse

33. Whiteboard Practice:
What kind of angle is this?
Reflex
Acute
Right Obtuse Straight

34. Whiteboard Practice:
What kind of angle is this?
Acute
Right Obtuse Straight Reflex

35. Whiteboard Practice:

36. Whiteboard Practice:
Classify each of these angles
138 12 246 90

37. Activity:

38. Answers:

39. Activity:

40. Answers:

41. Activity:

42. Answers:

43. Activity:
Question 8
Question 9

44. Answers:

45. Answers: 8
9

46. The robot is given a command to turn.
What command is it given?
Turn 60° clockwise

47. The robot is given a command to turn.
What command is it given?
Turn 30° clockwise

48. The robot is given a command to turn.
What command is it given?
Turn 100° clockwise

49. The robot is given a command to turn.
What command is it given?
Turn 45° clockwise

50. The robot is given a command to turn.
What command is it given?
Turn 160° clockwise

51. The robot is given a command to turn.
What command is it given?
Turn 50° anticlockwise

52. The robot is given a command to turn.
What command is it given?
Turn 120° anticlockwise

53. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle a?
a
40°

54. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle b?
b
30°

55. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle c?
c
110°

56. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle d?
d
35°

57. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle e?
e
145°

58. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle f?
f
80°

59. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle g?
65°
g

60. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle h? 180° +
h
20° = 200°

61. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle i? 180° +
i
60° = 240°

62. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle j? 180° +
j
100° = 280°

63. Measuring Angles
Align centre
Align 0
Count up
What is the size of angle k? 180° +
k
55° = 235°

64. l
Measuring Angles
Align centre
Align 0
Count up
What is the size of angle l? 180° + 150° =330°

65. To find this angle I just measure the smaller
angle and subtract that from 360°!
Does Anthony’s method work?
What method do you prefer?
360° − 35° = 325°

66. Align centre
Align 0
Count up
Measuring Angles
80°
145°
35°
110°
30°
40°

67. Align centre
Align 0
Count up
Measuring Angles
235°
280°
240°
200°
330°
65°