Ask Singapore Homework?
Upload a photo of a Singapore homework and someone will email you the solution for free.
Question
primary 5 | Maths
| Angles & Geometry
One Answer Below
Anyone can contribute an answer, even non-tutors.
Explain clearly.
Date Posted: 3 years ago
Views: 772
You labelled the 40 degrees correctly.
Now, the next focus is on triangle ABC. Do you know the sum of the three angles inside the triangle?
It's a fixed number - 180 degrees.
With this fact, we can add up the angles together. Let's call x as unit.
3 units + 4 units + 40 = 180
7 units + 40 = 180
7 units = 180 - 40
7 units = 140
1 unit = 140 divided by 7 = 20
So, x is 20.
Now, the next focus is on triangle ABC. Do you know the sum of the three angles inside the triangle?
It's a fixed number - 180 degrees.
With this fact, we can add up the angles together. Let's call x as unit.
3 units + 4 units + 40 = 180
7 units + 40 = 180
7 units = 180 - 40
7 units = 140
1 unit = 140 divided by 7 = 20
So, x is 20.
Thank you
This question is a good illustration /example of the property :
'exterior angle = sum of two interior opposite angles'
'exterior angle = sum of two interior opposite angles'
See 1 Answer
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
Hope this helps
Date Posted:
3 years ago
360 Tutoring Program