1. Angles and Parallel Lines
Sec One Express Mathematics ICT Lesson
Chapter 7:
Angles and Parallel Lines
7.3 Parallels and Transversals

2. Copy this slide into your Math book!
Instructions
Before we begin,
Those slides with 
Please do COPY it into your Math Book!
Your respective Math teachers will check them next week.
Copy this slide into your Math book!

3. This is the Louvre Museum in Paris, France.
It is one of the world's largest museums and a historic monument.
Question:
From this angle,
Are the lines on the Louvre Museum parallel to each other? Look closely.
Answer:
No, they are not…..

4. But in actual fact….
The lines on the Louvre Museum are parallel!
It’s the angle that we look at it. Now, we are looking straight, the lines are indeed parallel!

5. Copy this slide into your Math book!
Sec One Express Mathematics ICT Lesson
Parallel Lines
Lines are parallel if they never intersect and are always the same distance apart (equidistant).
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We show lines are parallel using arrows.
We write AB//CD. B A C D

6. Copy this slide into your Math book!
Sec One Express Mathematics ICT Lesson
Perpendicular Lines
Lines are perpendicular if they intersect at right angles.
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We use this symbol to show a right angle. A B C D

7. Copy this slide into your Math book!
Sec One Express Mathematics ICT Lesson
Ex 7.3 Practice Example 1 D E F G H I
Copy the diagram into your Mathbooks.
Fill in the gaps with // or
a) DE___HI b) DE___EF
c) GF___DE d) HG___GF
e) EF___DE f) HI ___ID
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Find as many parallel and perpendicular lines as you can in this photograph!

8. Copy this slide into your Math book!
Sec One Express Mathematics ICT Lesson
Ex 7.3: Exploratory Activity (1)
In your Math book, draw a line AB.
Draw another line CD on the line AB.
Copy this slide into your Math book! C D A B
Using a protractor, measure the two angles labelled with .
What do you realize?
Answer: ________________________________

9. Ace-learning Activity I
Sec One Express Mathematics ICT Lesson
Ace-learning Activity I
Now, log on to Ace-Learning and follow the instructions given in the next few slides.

10. Content Hub -> Exploratory Activities
Sec One Express Mathematics ICT Lesson
Content Hub -> Exploratory Activities

11. Exploratory Activities: Geometry -> Alternate Angles
Sec One Express Mathematics ICT Lesson
Exploratory Activities: Geometry -> Alternate Angles

12. Exploratory Activities: Alternate Angles
Sec One Express Mathematics ICT Lesson
Exploratory Activities: Alternate Angles
Follow the activities in this order –
Exploration, Understanding & Application!

13. Sec One Express Mathematics ICT Lesson
WHAT HAVE YOU LEARNT?

14. Alternate Angles Are Equal
Sec One Express Mathematics ICT Lesson
Alternate angles
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Given parallel lines,
with a line intersecting them both,
(called transversal line)
The marked angles are called alternate angles.
Alternate Angles Are Equal

15. Ace-learning Activity II
Sec One Express Mathematics ICT Lesson
Ace-learning Activity II
Now, back to Ace-Learning
And complete the Exploratory Activities: Corresponding Angles
Follow the activities in this order –
Exploration, Understanding & Application!

16. Sec One Express Mathematics ICT Lesson
WHAT HAVE YOU LEARNT?

17. Corresponding Angles Are Equal
Sec One Express Mathematics ICT Lesson
Corresponding angles
Given parallel lines,
With a line intersecting them both
The marked angles are called corresponding angles.
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Corresponding Angles Are Equal

18. Copy this slide into your Math book!
Sec One Express Mathematics ICT Lesson
Let’s try!
State ALL the angles that are equal.
State all reasons. j k i l n p o m f g h e d c b a
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19. Copy this slide into your Math book!
Sec One Express Mathematics ICT Lesson
2) Which lines are parallel, if any? Give reasons.
79°
77° A B C D E F G H I J
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20. 3) Below is a map of Tampines Avenue 8. Find angles a, b, c, and d.
Sec One Express Mathematics ICT Lesson
3) Below is a map of Tampines Avenue 8.
Find angles a, b, c, and d.

21. rules of angles Make a poster or booklet explaining the
Sec One Express Mathematics ICT Lesson
Chapter 7.3 Assessment
Make a poster or booklet explaining the
rules of angles
to the 2016 batch of Secondary One students.

22. Your poster or booklet needs to have: A title;
Sec One Express Mathematics ICT Lesson
Chapter 7.3 Assessment
Your poster or booklet needs to have:
A title;
A sentence and diagram explaining the terms Angles On A Line, Angles Around A Point, Vertically Opposite Angles, Corresponding Angles and Alternating Angles;
A sentence explaining what we know about these angles;
Lots of colour!

23. Now, move on to the last section
- Ex 7.4! 