What is the supplementary angle of 138 degrees? Here we will define the supplementary angle of 138 degrees, show you how to calculate the supplementary angle of 138 degrees, and even illustrate the supplementary angle of 138 degrees (138°) so you have a solid understanding of what it means.
The supplementary angle of 138 degrees, also known as the supplement angle of 138 degrees, is the angle that when added to 138 results in a sum of 180. Therefore, to calculate the supplement angle of 138 degrees, we subtract 138 from 180. Here is the formula, the math, and the answer:
180 - angle = supplement angle
180 - 138 = 42
42 degrees
138 degrees plus the supplementary angle of 138 degrees equals 180 degrees, which means that together they will make a straight line.
The illustration below shows 138 degrees colored in red and the supplementary angle of 138 degrees, which is 42 degrees, colored in green.
As you can see from the illustration above, 138 degrees and 42 degrees form a straight line together. This proves that the two angles, 138 degrees and 42 degrees, are supplementary angles.
Supplementary Angle Calculator
Let us calculate another supplementary angle for you!
Supplementary angle of 138.1 degrees
Here is another trigonometry math problem that we have illustrated and calculated the answer to.