What is the supplementary angle of 21 degrees? Here we will define the supplementary angle of 21 degrees, show you how to calculate the supplementary angle of 21 degrees, and even illustrate the supplementary angle of 21 degrees (21°) so you have a solid understanding of what it means.
The supplementary angle of 21 degrees, also known as the supplement angle of 21 degrees, is the angle that when added to 21 results in a sum of 180. Therefore, to calculate the supplement angle of 21 degrees, we subtract 21 from 180. Here is the formula, the math, and the answer:
180 - angle = supplement angle
180 - 21 = 159
159 degrees
21 degrees plus the supplementary angle of 21 degrees equals 180 degrees, which means that together they will make a straight line.
The illustration below shows 21 degrees colored in red and the supplementary angle of 21 degrees, which is 159 degrees, colored in green.
As you can see from the illustration above, 21 degrees and 159 degrees form a straight line together. This proves that the two angles, 21 degrees and 159 degrees, are supplementary angles.
Supplementary Angle Calculator
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Supplementary angle of 21.1 degrees
Here is another trigonometry math problem that we have illustrated and calculated the answer to.