Angles On One Side of A Straight Line
Angles on one side of a straight line will always add to 180 degrees.
If a line is split into 2 and you know one angle you can always find the other one.
30° + 150° = 180°
Example: If we know one angle is 45° what is angle "a" ?
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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" ?
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Angle b is simply 180° less the sum of the other angles. Sum of known angles = 45° + 39° + 24°
Angle b = 180° − 108° |