Angles

Nowadays in Math class, we learn about Angles and Triangle.  We have three rules about it.

1. “In a triangle, the 3 angles always add up to 180°”
2. “In a quadrilateral, the 4 angles add up to 360°” 
3. “Exterior angle equals the two interior opposite angles added together”

After that, we learn about how to find some angle by using those rules. for example:

 

In this triangle, it has 3 angles and they only tell us only 2 of them. How can we find another one? So we gonna use the first rule to do this.  The 3 angles always add up to 180°. So we need to take 180° – (70° + 50°) = 60°