Utilizing the supplementary relationship between angles 4 and 5, with the formula ∠5 = 180 - ∠4, the measure of angle 5 is determined to be 159 degrees.
The measure of angle 5 is determined by its relationship with angle 4, as they are supplementary angles, meaning their sum equals 180 degrees. The formula to find the measure of angle 5 in terms of angle 4 is ∠5 = 180 - ∠4.
Given that the measure of angle 4 is 21 degrees, you can substitute this value into the formula: ∠5 = 180 - 21. Simplifying the expression, ∠5 equals 159 degrees. Thus, the measure of angle 5 is 159 degrees, as determined by the supplementary relationship between angles 4 and 5.
This mathematical approach provides a systematic way to calculate angle measures based on their geometric properties, enhancing the understanding of angles and their interconnections within a given context.