What is the supplementary angle of 120 degrees? Here we will define the supplementary angle of 120 degrees, show you how to calculate the supplementary angle of 120 degrees, and even illustrate the supplementary angle of 120 degrees (120°) so you have a solid understanding of what it means.
The supplementary angle of 120 degrees, also known as the supplement angle of 120 degrees, is the angle that when added to 120 results in a sum of 180. Therefore, to calculate the supplement angle of 120 degrees, we subtract 120 from 180. Here is the formula, the math, and the answer:
180 - angle = supplement angle
180 - 120 = 60
60 degrees
120 degrees plus the supplementary angle of 120 degrees equals 180 degrees, which means that together they will make a straight line.
The illustration below shows 120 degrees colored in red and the supplementary angle of 120 degrees, which is 60 degrees, colored in green.
As you can see from the illustration above, 120 degrees and 60 degrees form a straight line together. This proves that the two angles, 120 degrees and 60 degrees, are supplementary angles.
Supplementary Angle Calculator
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Supplementary angle of 120.1 degrees
Here is another trigonometry math problem that we have illustrated and calculated the answer to.