Angles On One Side of A Straight Line
Angles on one side of a straight line always add to 180 degrees
30° + 150° = 180°
When a line is split into 2 and we know one angle, we can always find the other one.
Example: We know one angle is 45°, what is the other angle "a" ?
|Angle a is 180° − 45° = 135°|
This method can be used for several angles on one side of a straight line.
Example: What is angle "b" ?
Angle b is 180° minus the sum of the other angles.
Sum of known angles = 45° + 39° + 24°
Angle b = 180° − 108°